Christmas has come early for "Breaking Bad" fans: The "Complete Series" Blu-ray set is in stores today, and it's packed with commentaries and special features to go along with all 62 episodes of AMC's epic drug-trade drama.

But the 99.9-percent pure highlight for fans has to be "No Half Measures," the 2 hour and 15 minute (!) documentary about the making of "BB's" final season. The filmmakers had amazing access to the cast and crew throughout the production of "BB's" final eight episodes, letting us be a fly on the wall (or in the meth lab) as Walter White's long journey from Mr. Chips to Scarface draws to a close.

[Related: 'Breaking Bad' Spinoff Scoop From the Man Who Created Saul Goodman]

You should really watch the entire thing, but here, we've picked out 15 things the documentary taught us about one of the greatest TV dramas of all time.

1. "Breaking Bad" ended right where it began.

That flashback to Walt and Jesse's first cook at the beginning of Season 5's "Ozymandias"? That was the very last thing filmed on the series. We see stars Bryan Cranston (Walt) and Aaron Paul (Jesse) on that final day of shooting, in very different states of mind: Paul was sad and sentimental ("This day is just horrible. Awful."), while Cranston was a jokester till the bitter end.

In fact, in the very last scene the Emmy-winning co-stars shot together, Cranston dropped his trademark tighty-whities and did a take with his bare butt to the camera. Speaking of Heisenberg's undergarments…

2. We almost didn't see Walt in his iconic tighty-whities.

"BB" creator Vince Gilligan recalls shooting the pilot episode, with Cranston in nothing but undies and an apron. It was a cold morning, and Gilligan remembers giving his star a chance to back out, asking him: "How do you feel about the underpants?"

Cranston responded: "What's the most embarrassing thing I could be dressed in?" When Gilligan replied "tighty-whitey underpants," Cranston said firmly: "That's what I'm going to wear. Because that's what's right for the character." And a classic TV image was born.

3. Aaron Paul is a super-intense actor… even at the table read.

The doc shows the "BB" cast and crew reuniting to shoot the final eight episodes and sitting down for a table read of the first of the eight, "Blood Money." We see Paul and Cranston reading an emotionally wrenching scene, and even though it's just a table read, Paul is fully invested; we even think we saw tears in his eyes. Do they give out Emmys for table reads? If so, Paul gets our vote.

Get an exclusive sneak peek at the "Breaking Bad" doc "No Half Measures" right here:

4. It took hours in the makeup chair to become Walter White.

We didn't realize this while watching the show, but Bryan Cranston didn't just shave his head to become Walter White; he also put on plenty of makeup to play a gaunt, cancer-stricken Walt in the final season. We see Cranston in the makeup chair getting latex skin applied to his face to add extra wrinkles and what he calls a "turkey neck." "What we're trying to do is age him and decay him," the star says.

[Photos: Go Behind the Scenes of 'Breaking Bad']

5. Bryan Cranston can take a punch.

During the filming of the pivotal scene at the end of "Blood Money," where Hank confronts Walt about being Heisenberg (aka the "Tread Lightly" scene), Cranston wore two hats: actor and director. (Cranston directed three episodes of "BB," including that one.)

And he pushed for authenticity… even at the expense of his own face. The show's stunt coordinator Laurence Chavez says Cranston insisted on making Hank punching Walt look real, despite Chavez's objections: "You want to keep him safe, but you also want to get him what he's looking for." Plus, we get an intriguing look at an unused take of that scene, with a much more emotional Hank calling Walt to task for his misdeeds.

6. Bob Odenkirk wasn't a loyal viewer… even after he joined the show.

Odenkirk, who joined the cast as oily lawyer Saul Goodman in Season 2, confesses that when he came onboard, he wasn't familiar with the show: "The third season, I was in 10 or 11 episodes, and I still hadn't seen the show, even then. So I didn't know entirely what was going on or who I was talking about."

He adds that when Saul would be talking about Gus Fring or some other off-camera character, Cranston would sometimes have to explain to him who they were, adding: "You haven't watched the show, have you?" (Somebody buy this man the Complete Series Blu-ray set for Christmas!)

[Photos: 62 Things You Didn't Know About 'Breaking Bad']

7. Bryan Cranston and Aaron Paul prepare in different ways.

While the two actors get ready to film the tense park scene from "Rabid Dog" (where Jesse was supposed to lure Walt into a trap set by Hank, but threatened him instead), we get some insight into their acting methods. As Cranston says of Paul, "He prides himself on getting all his lines exactly right, and I pride myself on not."

We see Paul struggling to memorize his lines, and debating whether or not to just stick a copy of his lines on the pay phone he's using in the scene. Cranston says he'd be in good company: "Hey, Brando did it." Paul: "I'm not Brando, though." Cranston: "I meant Bob Brando." (In the end, Paul does the scene without any help, and nails it.)

8. By the time Hank died, Dean Norris already had his next job lined up.

We were all sad to see Hank catch a bullet from Nazi Uncle Jack in "Ozymandias," but there was a consolation prize waiting for Norris: a lead role in the CBS summer hit "Under the Dome." As Norris prepares for his last day of shooting, he tells the crew, "Catch me on Channel 2, muthaf--kers!"

Cranston offers his onscreen in-law a warm sendoff: "You're going on to CBS, where millions and millions more people will see through your inadequacies."

9. Every cast member got a nice parting gift.

Since the doc shows us the filming of all eight final episodes, we get to see each actor's last day on set. And each one of them received a sweet memento: a huge photo poster of themselves, signed by everyone on the crew. Cranston is there in person to say goodbye to Betsy Brandt (Marie), and points out his signature on her photo, along with his heartfelt inscription: "I would totally do her."

[Related: The 'Breaking Bad' Spinoff, 'Better Call Saul': It's Happening]

10. It actually snows in Albuquerque!

Yeah, we didn't believe it, either, until we saw the white stuff start falling just as Anna Gunn (Skyler) was shooting that grueling "Ozymandias" scene where Walt drives away with their baby. Gunn talks about how she had to keep Skyler's very frantic emotions going while they waited for the snow to taper off.

Plus, those snowy cabin scenes in the penultimate episode, "Granite State"? Not actually filmed in New Hampshire, but instead in the snowy Sandia mountains surrounding Albuquerque. (We never would've guessed.)

11. Aaron Paul is the best co-star ever.

OK, we kind of knew this one already. But the doc just provides more evidence of Paul's sweet nature, as he made sure to stop by the set for Odenkirk's final scene on the series in "Granite State" so he could say goodbye. He did the same for Gunn on the series finale, "Felina," even though he wasn't in either scene. And he's a hugger!

[Related: 8 Things We Learned About 'Breaking Bad's' Aaron Paul From His Reddit AMA]

12. Bryan Cranston and Aaron Paul read the final episode together.

The best part of the doc might be seeing Cranston and Paul sit down with a couple of beers and read the "BB" series finale together for the first time. The look on Paul's face when they get to the firefight at Uncle Jack's is worth the price of the Blu-ray alone.

After Cranston reads the final page of the script, he can't help but joke: "So I guess there won't be a sequel." But then he grabs Paul's arm in endearingly paternal fashion and asks him what he thinks, letting us see just how close these two are off-camera. (We miss them already.)

13. Yes, camera operators can cry, too.

One of the most emotional scenes in the "BB" series finale has to be Walt getting one last look at his baby daughter Holly before leaving on his final mission. Cranston says, "I actually meant to play that scenes without tears," but he couldn't help himself. And he wasn't the only one: A-camera operator Andrew Voegeli (a new father himself) was even crying while holding the camera! Well, at least he didn't mess up the shot.

[Related: 'Breaking Bad' Creator Vince Gilligan Shares 5 Alternate Endings]

14. Uncle Jack's hideout was as miserable as it looked.

The setting for the finale's climax — Nazi Uncle Jack's dank lair — didn't inspire a lot of fond memories from the crew. Gilligan says that set "was like hell. I hated just about every minute of it." It was claustrophobic and filled with smoke, he says, and Aaron Paul agrees, calling the shooting of that scene "a long, grueling, tortuous few days." (Still, better to be them than Uncle Jack or Todd.)

15. The final shot of "Breaking Bad" was a trick.

The very last image we see on "Breaking Bad" is a cool zoom-out on Walter's dying face as the camera pulls back into the sky. But the Nazi meth-lab set had a roof on it, making the shot impossible. So the crew actually re-created that exact set on a soundstage, so the camera would have room to pan up and capture that final shot. One last cinematic flourish in a series filled with them.

For all of these moments and more, check out "Breaking Bad: The Complete Series" on Blu-ray, in stores now.