I was in school today, I just came back from an overseas trip with a 13 hour time zone switch. I slept 7 hours last night although I usually need at least 9, and the time zone adjustment didn't help. I was completely exhausted. I messed up words, tripped, etc. all day today, so two of my friends asked why. I told them I didn't get enough sleep. 7 hours. They started laughing. One has insomnia. They thought I was ridiculous for being tired with 7 hours of sleep, and disregarded by explanation, although they asked for it.