The ending of the film isn't something we could expect but being in my early 20s I can completely relate to the inner meaning of the movie.
The line "Time waits for no one", which is focused again and again in the movie, tells the harsh reality of life. How we utilise our time and make choices as of this moment will define what our consequences will be in the future.
But it also tells us to enjoy as much as we can in between the rat-racing journey we call life, play baseball, appreciate art, enjoy the warm summer breeze, have fun with friends while it lasts. Cause time will destroy/ burn everything in the end.