Is Not Finishing a Book a Crime?

I have always tried my hardest to finish books that I start, so I'm feeling pretty bad that I had to quit reading Running Man by Michael Gerard Bauer. It was the kind of book that requires a lot of thinking and analyzing, and I'm sure it's a great book, I just wasn't in the mood for anything that required my brain to do much else other than read. To make it worse, I got that book for free! Eek! I'm wondering if any of you guys will quit a book, and for what reason. What reason is plausible? Or do you always finish your books?

I'll try to get another review up soon!