tiredness

ok i am so tired and i don't really know why.
sure i have had a couple of late nights but i shouldn't be this tired i am having trouble texting and typing ?!?!
usually this would mean i was mistaking tiredness for depression but no, i am really happy. my life, although i sometimes don't think so, is going really really well.
i will give you an example - this time last year i could not name 8 people who would count me as a mate, and now i have a whole group of friends who i know sometimes i don't deserve. so thanks, i do appreciate you.
its odd how you realise this stuff when you are tired