Certainly true, but sleep seems so... well, unused. There's an obvious reason why you eat or use the toilet, but there is no immediately obvious reason why you'd need 8 hours of sleep every day. (I could understand something like 30 minutes, maybe, but 8 hours?)

Of course, you're also right insofar as that life without sleep wouldn't be fun, but that's just the point - it'd be nicer if we didn't have to sleep so that life could still be fun even without sleep. :) (At least *necessary* sleep.)