"I'm the only one who's gonna remember that, because people only think of themselves. Nobody cares, you know?"
Troy was only talking about the embarrassing moment Brad caused at the interviewing office, but it reminded Brad of what his rich friend said about not viewing him as a competitor, ever. People didn't care how successful he was or what he had, in the end what mattered was just him being happy. Learning that his old professor had died made him realize that life goes on and flies away, and it all came down to understanding that instead of comparing himself to others and wanting to have it all, he needed to notice all the good things he had and just enjoy life.
Troy himself is a chill guy who isn't pressured by success rates and in the end he just wants to do what he likes.
It's a good message and a good plot, but 2 things make this movie worse than it would have been.

1- Ben Stiller is a really terrible actor. He made the same staring face the whole time and it almost felt like he was creepily watching his son at some parts, he even gave that same look at the last scene when he was looking at Troy as he slept.
2- The annoying narrator voice. This diary style of story-telling by the main character himself is becoming really cliche and it should only be used for about 5 minutes into the movie. If not, it at least shouldn't be overused and it should be done at the right time (like in Forrest Gump) and the important thoughts should be understood in other ways. This is a movie, not a book in first person. "Show, don't tell" right?