Books you've read halfway through but didn't finish.

I don't think I've ever done this, which is what sparked my curiosity. If I've read a book more than halfway through, the momentum is always enough to carry me to the ending. Or maybe it's just sunk-cost fallacy. But I wonder whether anyone here has had a book that they've gotten more than halfway through but couldn't bring themselves to finish, and why?

EDIT- I command legions.