Warning: Spoilers ahead for The Big Bang Theory.

He celebrated his Emmy win for The Big Bang Theory last year and his 50th wedding anniversary with wife, Ginny, by grabbing pizza and beer, so how will comedy legend Bob Newhart celebrate his 85th birthday in September?

"We might even go for an entrée this time," Newhart jokes to Yahoo TV. The comedian and actor, whose win for The Big Bang Theory was, surprisingly, his first-ever Emmy win, has a lot to celebrate these days, with his role on the hit CBS comedy likely to continue (despite Professor Proton's demise), his standup comedy career still going strong, and the release this week of The Bob Newhart Show: The Complete Series on DVD.

The series, Newhart's first big sitcom hit, aired from 1972-78 on CBS, where it was part of a Saturday night lineup that is among the most stellar in TV history. Newhart talked to Yahoo TV about his show and its place in the classic TV-packed schedule, one of his most favorite episodes of the show, the future of Professor Proton, and why standup comedy keeps him young.

What was behind the decision to release The Bob Newhart Show complete series boxed set

now?
Fox originally was distributing the show, but they only put out the first four years. I was getting correspondence on the Twitter account and the Facebook account saying, "When are the fifth and sixth [seasons] coming out?" If you do the first four, you really should do the fifth and sixth. When Shout! Factory came along and said they were going to do it, my immediate concern was for the people who had already bought one through four. We worked something out with them so that the people who bought those aren't going to have to buy the whole six years. I was very happy.

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Will we see that happen with Newhart eventually as well?
I think so, because they're into their third season [of Newhart] now, and Newhart went eight. When Shout! Factory starts something, they finish it. The first two years of Newhart, they weren't that great. We were kind of finding our way, and it really happened in the second year when we brought Julia Duffy in, and then definitely the third year when we brought Peter Scolari in. Then we introduced the television program [within the show], Vermont Today, which gave us a whole new area to go into.

Did you have those feelings about The Bob Newhart Show in the beginning?
We made those changes before it went on the air. The original pilot was [Suzanne Pleshette] and myself, and Peter Bonerz was another psychiatrist. The concept [revolved] more around the condominium and condominium meetings. Between that time and the time we actually aired the pilot, we added Bill Daily [Howard], and that was a great addition. Whenever we had a script and it wasn't working, we just wrote in Howard, and he said something ridiculous. We didn't have Marcia [Wallace] yet. Marcia was the result of … We got a call from Grant Tinker. He, along with Mary Tyler Moore, and Arthur Price, formed MTM. Either [CBS president] William Paley or his wife had seen her on a Merv Griffin show and thought she was very funny and said, "She'd be very good on what's-his-name's show."

Watch a clip of Newhart on Saturday Night Live:

Do you have a favorite episode of The Bob Newhart Show?
One was on the other night, on MeTV. I call it the IQ show ["Mister Emily Hartley"], where Emily and I both take an IQ test. She tells me my score was 129, and she says, "Oh, that's almost gifted." I ask hers … "Well, it's 151." The show continues, and I'm miffed … She said, "Bob we have a perfect marriage." I said, "No, we don't have a perfect marriage. A perfect marriage is when the husband and the wife have the same IQ. And the second-best marriage is where the husband's IQ is one point above the wife's. The worst marriage, which is our marriage, is where the wife is 151 and the husband is 129, which is a difference of, uh, a difference …" and she says, "22."

That really does sum up why their marriage was so great, though, doesn't it?
That, and the fact that we didn't have kids. I didn't want to do that kind of show where Daddy was kind of stupid and getting himself in all kinds of trouble, and the kids would huddle together and say, "How do we get Daddy out of this?" That wasn't the kind of show I wanted to do.

Newhart shares his TV memories with Chuck Lorre:

The Bob Newhart Show aired on Saturday night, as a part of a block of huge hit shows. We forget now how big Saturday primetime used to be.
Yeah. It was All in the Family, M*A*S*H, The Mary Tyler Moore Show, us, and The Carol Burnett Show.

Most networks would kill to have all of those shows across their whole schedule now, let alone on one night. That really is one of the best nights of TV programming in the history of TV.
It probably compares to the Lucille Ball era and the Milton Berle era, where people stayed home and restaurants complained about the fact that nobody was coming in. I really was proud of the show. I thought it was well-acted and well-written. We kind of lived in the shadow of The Mary Tyler Moore Show. They got all the accolades. [Before] our sixth year, I went to Bob Wood, who was head of entertainment for CBS and a friend. I said, "Bob, would you move us, because I think we're doing good stuff. I think we can hold our own." I may be the only person who ever asked to be taken out of a hit time slot and put somewhere else. He said, "Hey, look, it ain't broken, so we ain't gonna fix it," so we stayed there.

You ended The Bob Newhart Show, and Bob and Emily moved to a small town in Oregon, and then Newhart picked up just four years later with Dick and Joanna having moved from New York City to a small town. Is it true you had briefly considered coming back with a new show featuring Bob and Emily?
Yes. I thought to myself, everything worked so well … why don't we pick up with Bob and Emily in Oregon? He became a professor at the college, and we'd still have Marcia and Billy, and we could still have Mr. Carlin [Jack Riley]. But the more I thought about it, and I talked to Suzie about it … we'd [done] six years of shows already, used six years of ideas. I thought maybe we'd better scrap that and start at the beginning.

[Related: 'Big Bang Theory' Postmortem: EP Steve Molaro on the Future of Bob Newhart's Professor Proton]

Belated congratulations on your Emmy for The Big Bang Theory. Did it mean as much to you at this point of your career as it would have for The Bob Newhart Show or for Newhart?
I think so. It's one of the moments I'll always remember. The Emmys are special because it's your peers. The fact that they stood up and gave me a standing ovation … I don't know if that would have happened if [I had won it] in the third year of The Bob Newhart Show. The ovation was for a body of work, I think.

Were you sad they killed off Professor Proton?
I don't know. I'm not sure where they're going to go with that. My original deal with Chuck [Lorre] was three episodes, which is what I wanted to do. I didn't want to be a regular cast member. The show is so great, and I didn't want to disturb that at all. I think they've left it hanging open, though. I think there's a possibility of [Professor Proton/Arthur Jeffries] returning as Obi-Wan.

See Newhart on The Big Bang Theory:

And you had fun, you're open to returning?
Oh, yeah. It's a delightful show, it's very easy. The hours are wonderful. Great people to work with, and it's good writing. I've been telling people I wanted to do television, because I still have my fastball. It turns out it's more like a changeup than it is a fastball.

Has the experience given you a desire at all to do another series of your own?
Oh God, no, oh no. Kim, I'm 84. My wife would divorce me if I were to do another show, she would just leave. We're married 51 years, so she's in from like the first dollar, so no. I can't take a chance like that. It's a young person's world now. It isn't so much it's physically tough, though it is. It's the dealing with the disappointment if it doesn't work. Emotionally, I wouldn't want to go through it again. It's just something I wouldn't want to do.

What makes you continue to perform standup? What is it that still draws you to the stage and to the audiences?
The alternative is Sunset Boulevard. It's sitting in a darkened room and Erich von Stroheim coming in and saying, "Which episode of Newhart would you like to watch today?" I don't live in the past. It's very easy at 84 to live in the past. I have heard of stories where that's what some people have done, actually spent their last years just reliving their life. Standup is where I started, and I enjoy it. It's inconvenient, the air travel, losing the luggage, having to catch these little regional jets. But once you get there, once you're on stage and you've got a good audience … I could never give that up as long as I have my health.

The Bob Newhart Show: The Complete Series is now available from Shout! Factory.