I do the same thing. I think I've read a few of my books over 10 times each.
I refuse to lend my books out. No one will take care of my books the way I do. I dread getting a book back and have pages bent, or the spine messed up. Nope, Not happening.
I understand, but I love the idea that I'm sharing something I really like and that the person I'm lending my book to will be getting lots of joy out of it.
I'm sooo freakin' nice it kills me