I can never remember what happens in the books I read, the main plot turns or even the characters names sometimes. Yet when I read the book again for the 2nd time, it is never the same and I get bored really quickly.
How do I hold information better?
Why would you want to do that? There's Wikipedia for that.
OP, you read to live the experience of reading a work of literature, not to remember "what happens" in it. Think about it this way: does knowing the details equal reading a book? No? Then having read it does not imply remembering such details.