Recommendations

It's a little ridiculous that I haven't posted a review here in so long...but I'll confess, it's because I just haven't been able to get into and finish a book lately. First, I started an ebook I'd purchased on sale a while back. It wasn't bad just...I couldn't get into it. I can't decide if I just wasn't in the mood for teen dystopian...or if it's just not my favorite genre. So I put that one down and picked up a historical fiction (technically, a contemporary fiction written during WWII). I am very interested in this book in theory...but again, either I'm just not in the mood, or there's some other reason it's just not grabbing me. Normally, I'd just put it down and try again another time, but it was a book loaned to me by a friend who said "read this! it was so good!" And I've had it for more than a year. I feel a compulsion to read books recommended by friends, and this one especially since I really want to get it back to the friend.
A prime example of why in Reader's Advisory the rule of thumb is "suggest" don't "recommend."
Do you feel compelled to finish books you start? Does it make a difference if a friend gave it to you or recommended it?