How the heck can I be tired after 12 hours of sleep?!

I'm serious! I took a 3 hour nap from 6 to 9 last night, and missed dinner. Then, I fell asleep from 9 to maybe 6 or so this morning. That's 12 hours of sleep! How the heck could I wake up feeling tired?! Oh well. Doesn't matter. I feel fine now. Gotta get my work done quickly so I can go to the new bleach movie tonight! It's going to be awesome! I can't wait to go with Ian!