What Happens When You Forget Your Book?

I can't be the only person on this planet who goes nearly insane when I forget to bring a book with me when I go somewhere I KNOW I'm going to need to wait for awhile. You'd think that after 30 something years (and that's all I'm going to admit to) I'd learn. You'd think that with 13,000 books at my disposal I'd always remember to take one. But nope. I often find myself with downtime and nothing but my own thoughts to keep me occupied. Sometimes if I'm fortunate I have a piece of paper with me so I can make lists, which I rarely heed, or I can write inane blogs like this one, long hand. I also practice the long standing art of people watching too. Usually when I do that I am mentally writing scenes and plot twists for books I know I'm going to write someday.

Does anyone else care to share how they keep sane when waiting without a book to keep them occupied?