One time when I did this my pen flew across the room and smacked my friend in the face. I had the hardest time holding back my giggles while she stared at me so confused as to why I threw my pen at her.
I do this more often than I'd like to admit. I count wondering if I really want to read more, then I start reading more, get hooked, and I end up not being able to put the book down until I get the answers I want. Only for school books tho lol