Perhaps he came to the (very probably mistaken) belief that the world was better off without him. Sometimes something can get irrationally stuck in your head and nothing will shift that thought. For some this leads to the belief that it's not worth them being here. Some however may just want to know what comes next or feet that no matter what it is it has to be better than this.
I just hope you can personally find an answer that helps you come to terms with what has happened.
I just hope you can personally find an answer that helps you come to terms with what has happened.