In the relationship department, it is Celeste who appears to not know what she wants. Jesse, who is used to waiting things in life out, is also waiting for her to come to her senses and take him back. It really isn't discussed what broke them up to begin with, but in the first act it is he who is more clear about what he wants relationship wise. Things hit a snag in act two, which is when Jesse finds out he is going to be a dad. This life changing news throws Celeste and Jesse down different paths. Jesse starts the transformation away from being a Lost Boy, getting a steady job, eating healthier, and embracing this life change with an open heart. He isn't the typical Andy Samberg character anymore. Jesse isn't with his moments of doubt, but on the whole the experience has taken him from the side lines into the game and he's ready to play.
Celeste on the other hand devolves professionally and personally after Jesse's bombshell. Her stellar career as a trend analyzer hits a snag, she makes some professional gaffes that shockingly don't get her fired. She slowly starts to unravel personally after hearing the news that Jesse is going to be a father. She shows up to parties and becomes the Nick Nolte of the group (never a good sign) and is forced to admit when she sees the new and improved Jesse that maybe it was her- she'd been holding him back. She would divorce herself to improve her situation, but seeing as that isn't quite legal yet she takes solace in alcohol and weed.
It is somewhere around the passed out Celeste in the pool and the vegan meal that the tears really starting flowing. Can you have it all? Apparently the overwhelming answer is no. And not have it all as in the great husband, the adorable kids, and the fulfilling career. Having it all as in being right and being happy. While not always mutually exclusive, the root cause of Celeste's downward spiral is her insistence on being right at whatever personal cost to her own happiness. She isn't wrong in thinking Jesse isn't a good provider with a great career ahead of him. He doesn't even own a car and would rather be surfing than working. But what she fails to embrace is that Jesse is happy, in spite of his wrong choices.
Celeste is paid to analyze trends and she's good at her job . She is so good that she is even right about people's motivations and limitations. But being right isn't everything, and that is a hard lesson for Celeste to learn. What's the song, If it's wrong, I don't want to be right? What Jesse learned way before Celeste is that being wrong may ultimately make one happier. And that is the curse of the human condition, we are logical enough to know right from wrong. Yet we're not guided by logic alone, we have feelings. And sometimes being happy means being wrong. Perkins does it again, wisdom nugget mined and message received.