The brain tumor joke was not funny
In the scene where Owen Wilson's character tells his girlfriend that he's gone back in time to meet all of his favourite writer idols, she tell him he's suffering from a brain tumor.
I really don't understand how people can find that someone with a brain tumor hallucinating and acting crazy funny. I'm saying this because my dad died of a brain tumor, and he was acting very strange towards the end of his life. It was a horrible experience for me and my family, and maybe worse for others so I really don't get people would find it funny.