Figure out this riddle if you can?

once there was a boy and all he was was a head, every day his head sat in his room listenin to the kids playing outside and wished he had a body so he could go to the window and watch, lo and behold the next morning he had a body so he shuffled acroos the room and watched them playing basket ball, he wished he had some arm so he could catch the ball and lo and behold he woke the next morn with arm and shuffled out the door to play basket ball, on the basket ball court he watched the kids running around the track and thought if only i had legs i could run faster than any of those and lo and behold the next morn he woke with legs, he got up and ran out the door and SMACK was killed instantly by a car on the road.......now Whats The Moral of This Story