It's official. Rebecca most likely has Alzheimer's.

This Is Us Season 4 Episode 15 presented some poignant memories for her as she and Kevin went on one last outing before she had her MRI.

It made for an effective, emotional hour of television, especially juxtaposed with Randall's therapy session.

This Is Us is, at its heart, a story of several successive generations of a family told simultaneously.

The multi-timeline format has contributed to the poignancy of Rebecca's Alzheimer's diagnosis because viewers are treated all at once to both her youthful escapades and her desire to hold onto her memories as her mental faculties begin to fail.

The three parallel journeys Rebecca took during the hour drove that point home even more so than other episodes of the series.

Kevin: You still got it.
Rebecca: An otherwise simple morning would have been forgotten if it weren't for that song.
Kevin: Are you scared?
Rebecca: A little, but why am I talking about that now? I'm here with you. You always make everything fun.

Permalink: A little. But why am I even thinking about that now?

This particular story also gave us a glimpse into Rebecca's relationship with Kevin, something which is sometimes neglected in favor of her relationship with Randall.

Kevin's journey from the disruptive child who manipulated his way into a trip to the baseball card store to stepping up to take care of his ailing mother was fantastic.

Thank goodness Randall let it slip that Rebecca was having cognitive issues because otherwise Rebecca would have been cheated out of spending the time she needed to spend with Kevin to try to keep her mind off her appointment.

Contrary to what everyone expected, Kevin didn't fall apart when he learned about Rebecca's diagnosis. He stepped up and gave her the kind of gift only he could give her.

And in return, Rebecca gave Kevin some rare and much-needed encouragement. While his role in the family might have been as the "problem child," Rebecca loved him for his free-spirited, so-called disruptive nature.

He needed to hear that as much as she needed to hear that he'd be there for her throughout her illness.

The journey Kevin and Rebecca took was more or less through memory lane.

People with Alzheimer's and similar disorders often have clearer memories of the past than the present, so it was unsurprising that Rebecca became nostalgic about the Joni Mitchell albums, and Kevin's offer to take her to that house was a sweet gesture.

I'm good. It's funny, all this bad news has kind of freed me up. Carpe diem and all that.
Rebecca

Permalink: I'm good. It's funny, all this bad news has kind of freed me up. Carpe diem and all that.

One thing that surprised me was that going into a record store didn't make anyone think about Kate and Marc.

This wasn't Kate's story, but still. She met Marc in that record store, and as soon as Rebecca mentioned records, that's where my mind went.

Anyway, Kevin's stepping up to be there for Rebecca provided a compelling contrast with his childhood adventure with her.

Pre-teen Kevin might have said Sophie's mom was more fun, but he relished the opportunity to spend time alone with Rebecca more than he let on.

The two of them had a great time searching for that baseball card just like they had a great time checking out Joni Mitchell's old house.

Therapist: So what brings you here today?
Randall:It's kind of a long story. You got an hour?

Permalink: It's kind of a long story. You got an hour?

Kevin and Rebecca's lighthearted pre-diagnosis outing stood in stark contrast to Randall's therapy session.

The therapy scenes were extraordinarily well done and realistic. Even going to a therapist's office at all is a huge step for someone like Randall who, as he said, has control issues.

Randall has completely bought into the idea that he is the only one who can hold this family together, and he probably won't be too happy to learn that Kevin did just fine at taking care of Rebecca.

Randall: I have anxiety. Suffer from? Is that the... doesn't matter. Maybe once a decade things get overwhelming. I have a panic attack, end up hospitalized. My house was recently broken into and my wife is worried about history repeating itself. My daughter Tess has panic attacks and she's seeing a therapist and it helps. So that's what I'm looking to get out of this, I guess. Coping mechanisms.
Therapist: Before we get to all that, I'd like to know a little more about you.
Randall: I'm an open book. What do you want to know?

Permalink: I'm an open book. What do you want to know?

He certainly didn't want to hear the therapist's opinion of his need to be the caretaker in the family. Thank goodness Beth talked him into going back.

Beth's impassioned plea for Randall to do what it took to be okay so she could confide in him that she wasn't okay either was one of the most powerful Beth/Randall moments on This Is Us Season 4 thus far

She was right, too. Randall needs help, and one of the things he needs help with is finding a new definition of who he is that doesn't include being the glue holding the family together.

Randall and Kevin are headed toward a showdown over Kevin's contributions to helping Rebecca.

Most likely, this is what's going to lead to the rift between them, and that's a shame.

Dealing with Alzheimer's isn't easy for anyone, and Randall and Kevin should be sharing the load, not fighting over who gets to burn himself out being the sole caretaker.

Anyway, while Randall might not have wanted to think about his childhood relationships with his family, viewers certainly got to see where some of his habits began since Jack encouraged him to take up running to deal with his anxiety.

Meanwhile, thank goodness Kate and Toby came to an understanding, at least for the moment.

I'm still firmly in the camp of believing that Kate is way overreacting to Kevin and Madison's hookup, but in any case, Madison's advice to Kate was perfect.

Hopefully, Kate can stick to her resolve to stop resenting Toby for his feelings and stop fighting with him over everything.

That music studio Toby built in the garage wasn't only a sweet gesture, but appears to be an important part of Jack's childhood, maybe even contributing to his decision to pursue music as a career when he grows up.