Do we really need to sleep?

Everybody ask if we really need to sleep.
We're accustomed to sleep and tell us we have to sleep but why we recommend it? The traditional theory about sleep is that our brain needs to refresh itself and to file in our memory everything that has happened to us during the day.
We can put off sleeping for a limited period, for instance if we go to an all-night party, but sooner or later we have to sleep.
If we are not allowed to sleep we can suffer unpleasant symptoms and we have disobeyed our brain's programming, and we can suffer hallucinations and eventually die.
In conclusion, I think that we really need to sleep to lead a normal life.