why????

why am i tired....but i can't sleep.....i can barely keep my eyes open....but the second i go lay in my bed.....i'm wide awake....its not like i have a ton of stuff to do......yes i have homework.....and i little geography quiz tomorrow....which i've already studied for......and i know at least 10 of the countries on the map....and where they are located....so i'm good.....after school i'm going to sk8....and then i'll come home....nothing new....nothing exciting....at least not more exciting than my normal, daily activities....yet i can't sleep.....it makes no sense......