This sires was one of the best I've watched so far, so much mixed feelings and lovely moments but the ending was very confusing, can some one pls help me with it!!!

Can someone just explain what happened at the end? why did he say "i will miss u!!!" an go
Can someone just explain what happened at the end? why did he say "i will miss u!!!" an go
Can someone just explain what happened at the end? why did he say "i will miss u!!!" an go
Can someone just explain what happened at the end? why did he say "i will miss u!!!" an go