Sticky notes are fun to draw on. I don’t know if it’s an everybody thing or just an animation thing (before digital became the norm, they were the de facto method of making adjustments to designs and storyboards), but I’d bet there are more post-it note doodles out there than actual post-it notes. I always keep a pad nearby, and I find myself drawing on them when I’m listening to a sermon in church, or sitting in a hospital room waiting for my brother to pass a kidney stone, or anywhere else with a little time to kill. But most of the time it's while I'm on the sofa watching a little TV before bed. I find it a nice way to unwind when I’m too tired to read.