Same here. Apparently I've ALWAYS been like that.
I obviously don't remember it because I was like 2 or 3, but my mom says that when I was a small child, she couldn't give me a big coloring book anywhere near bedtime. She said she did it once or twice, and I'd sit and try to finish the entire book, like my life depended on it. When she'd try to put me to bed, I'd cry and just freak out like I had something important to finish.
She finally realized she'd let me just keep coloring, and I apparently fell asleep trying to finish the book. She said I got almost done before I literally passed out from exhaustion, and she put me to bed after I passed out coloring (I mean, like hours later, like 1 or 2am). She just tested it to see what I'd do.
The next day, I apparently woke up and hurried to it to make sure it was okay, and before eating anything, I had to finish it. And I did, according to her.
Later, she learned to only give me small coloring books, and much earlier in the day. I had an aunt who got me one of those "TWO HUNDRED PAGES OF COLORING FUN!!!" type books, and she nearly strangled her.