Fun With Notebooks

It started in elementary school and hit its apex in high school, but still continued in College and university, though I was more prone to sleeping when I got to that level...

The minute I got bored in class, I would start drawing in my notebooks and manuals, from scratch if there wasn't anything, or using a pre-existing picture if possible. And it seems I am not alone, as this site showcases 22 fun examples, among which one really resembling what I'd do: