This Is Us : First Trailer of Season 6 Shows Mandy Moore's Rebecca Pearson Fearing Memory Loss

This Is Us fans, grab some tissues and brace yourselves for the final season.

On Thanksgiving Day, the Pearson family's most sacred holiday, NBC aired the first trailer for season 6 during the Macy's Thanksgiving Parade broadcast.

In the first look at the upcoming season, Rebecca (Mandy Moore) wonders about the memories she will still be able to remember as her Alzheimer's progresses. "I'm losing my memory. Sometimes I think about what my very last memory will be before the candle goes out," the matriarch says as highlights from all five seasons are recalled.

"I'm not worried about forgetting the big stuff, it's the little things I'm not ready to let go of yet," Rebecca admits.

The final chapter of This Is Us will consist of 18 episodes and kick off with the Big Three celebrating their 41st birthday as all seasons have traditionally started with Kevin (Justin Hartley), Kate (Chrissy Metz) and Randall (Sterling K. Brown) on their birthdays.

"The memories we share are never forgotten," a banner message in the clip reads. "One final chapter, so many chances to make this moment last."

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"Mandy is going to have a tremendously ambitious season next year as an actress," creator Dan Fogelman previously said about her character's ailing health.

"Obviously, as you're traversing this timeline, these timelines into the future and her character battling Alzheimer's, it's going to be quite a showcase for a young woman, who I've been beating the drum for a while, is doing something quite extraordinary on television. So that's a big storyline to come," he said.

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Audiences were first introduced to the Big Three and their parents Jack (Milo Ventimiglia) and Rebecca when season 1 premiered on Sept. 20, 2016. Since then, the family has expanded with series regulars Chris Sullivan, Susan Kelechi Watson, Jon Huertas, Ron Cephas Jones, Caitlin Thompson and more playing crucial roles.

As fans will recall, season 5 ended with one couple calling off their romance while a flashforward teased a Pearson family member's second wedding.

When the season 5 finale aired in May, Fogelman told PEOPLE and other reporters that "everything will be resolved" by the end as audiences will get a "real sense of resolution and completion from this family."

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Speaking about the final season, Metz previously said "the last season is going to be pretty amazing," with Ventimiglia noting, "I think the audience can expect a lot going into that last year. I think it's going to resonate and stay with people for a very long time."

Moore also assured fans that they will get to see an ending worth the wait. "People have been very patient. That patience will definitely be rewarded," she said.

Brown previously told PEOPLE, "The relationships that you see on screen are not anything that is faked because the love that we have for each other in real life is real. More than anything, I'm going to miss my family so much."

Season 6 of This Is Us premieres Jan. 4, 2022, on NBC.