I'm a well read grad student who's bluntly honest about all things, although I try to be most honest about myself.
And, well, he's not really a reliable narrator. He breaks the fourth wall, he lies, then says things are sorta-kinda-partly the truth, and so he's not really lying to you completely. You know part of his story is bullshit because one story is wrapped in another.
There are two conflicting possibilities and only one can be true.
Endings that leave you wondering this? They're wonderful. And this was great until the ending scene, where the book - and Deadpool - spelled it all out. You'll never know, there are two possibilities, and we're not telling so make of it what you will. The problem is that worked out quite nicely until I was directly told. Only then did this pull me out of the story.
Still, I was entranced until then. The art and story, the questions it was bringing up, all were quite lovely.