can't wait

what i find to be a rather interesting concept is when people say "i can't wait for [fill in exciting news here]" So when people say they "can't wait"- can't is a word that implies its not possible, or willing to be tried, SO when you say you cant wait, is that true? i mean, if you REALLY cant wait, what are you going to do i mean because it CANT happen, so what are you going to do? If fact i think you really can wait, otherwise you might implode from all the excitements in your body.