Thinking about how the first time you watch through YJHD, you think Aditi and Avi are going to have a DDLJ situation - with Avi having to win over Aditi and stop the marriage. And that seems like the logical progression, given a: the amount of Bollywood movies with this trope, b: Taran's introduction being mostly humour making fun of him, and c: Avi's line where he asks Aditi why she is getting married. Surely, all the points lead to Aditi and Avi secretly being in love with each other and now we must watch them both realize this and stop the wedding in its tracks.
The moment this changes is what Bunny, like the audience, asks Aditi about her relationship with Taran, and her crush on Avi, and we learn that she is well and truly over him. When you watch over the movie again, everything about these scenes change. Aditi crying before the intermission is her finally mourning her unrequited love, and then putting it to rest when she says they are no longer kids. And Avi asking her why she is getting married is not some kind of implication about him being in love with her, but rather an insight into how Avi feels like everyone around him seems to be moving too quickly, far ahead of him.
Bunny is building his career and travelling the world. Naina is a (implied) respected doctor. And now his last link to childhood, his best friend Aditi, is getting married and getting on with her life. Meanwhile, most of Avi's attempts to build something for himself have failed, and he has reached that classic quarter life crisis where he is falling behind and nothing is getting better for him, while everyone else is doing well.
I love YJHD, though I do wish that a: we could have seen Naina as a doctor and b: we could have had an uplifting ending for Avi. His ending is tinged with hope, that this is his rock bottom and that he has a chance to get better if he so chooses, but that is his choice that he has to make, and the movie leaves it open-ended for us to decide if he makes that choice or continues to spiral. So maybe it was a better option not to leave it open-ended.
Because if you really think about it, the characters in YJHD are often defined by a certain struggle people in their twenties/early thirties report to feel. Bunny, even after the intermission, is implied to be finding some doubt in his lifestyle choices, especially when he is missing so much of his loved ones' lives, and has to choose if he wants to make that change or not. Naina is also challenged in a similar way, initially on the trip where her self-perception and desires are challenged, and at the wedding where her current lifestyle and again her desires are questioned. Should she make the impulse decision to go on the trip, even though she always perceives herself as someone who thinks things through? Should she go to the party, even though she doesn't think she's cool? Should she start a relationship with Bunny, when she doesn't want to leave her family, friends, and life behind?
Aditi is experiencing a complete lifestyle upheaval by getting married. In fact, she the one who reminds the others consistently that they are growing up so fast and are no longer kids. Its significant that it is her wedding that causes the other characters to reconvene. She was the steadiest in character during the first half of the movie, and still is in the second half, but she has changed drastically in between. Her steadiness, presence, and experiences act as a backdrop for the other characters to evolve. She is a representation of growing up, of getting older, of time. She learns most of the lessons before the other characters do, and so acts as a mentor to everyone else. She inspires Naina to go on the trip, and tells Avi to lock in and stop gambling, and helps Bunny recognize his love for Naina. So, when Avi asks her why she is getting married, he is mourning the fact that even the rock of the friend group, who also ironically represents time, has moved on from where he is stuck at. Time has moved ahead of him.












