Board Thread:General Discussion/@comment-4427410-20160805014450/@comment-25322628-20161003052037

Banner could have picked it up out of controlled anger that got the better of him; when angry, people will do unexpected things that are influenced by anger.

He could've been lost in the revelation of how he tried to commit suicide once and found that to be impossible for him, forcing him to move on and find a way to live with the Hulk.