Randall reflects on what could have been.
However saying that [spoiler]..the end of the episode having Randall guilt [?] his Mother into promising to take the clinical trial was a little off.
The therapist having drawn out that he still felt residual anger with Rebecca about not telling him about his birth father...results in him phoning Rebecca telling her, he's been a good son and never asked for anything...then telling her she should do the trial...
Maybe it's just a prompt for more conflict..at some point we know Kevin and Randall are not on speaking terms..maybe it's from this.
Knowing This is Us there's a long term payoff here, there always is...Randall has a lot of issues on display..
Bonus: The appearance of Better Things Pamela Adlon as the therapist was great..the perfect Rebecca substitute.