My boyfriend keeps some of his ex’s stuff!

Ladies I’m so confused here! My boyfriend told me that he keeps all the cards / notes his exes wrote him. Now I wouldn’t normally freak out but they are all cards and notes saying how much they love and and want to be with him forever. But he hasn’t saved any of mine. I’ve been with him four years and it kinda bothers me a bit that he still has these love letters! On top of that his Netflix password is his ex’s name. He gave it to me when I got logged out! Is this weird? All my friends think he’s not over her if he has all this stuff.