What is 'sleep'?

<p>I don’t think I’d ever get used to it. Even when I only get 6 hours of sleep I get tired easily during the day and I’ve been doing it the whole school year. I guess different people need different amounts of sleep. I need at least 8 hours to do well.</p>

<p>@dsi411 Caffeine helps, too. My friend never drinks it, stays up til 2-3ish and only gets 3-4 hours of sleep. I have no idea how he does it.</p>