Rather like a hedgehog or a dormouse, the mighty Apocalypse actually hibernates - only his stretches of hibernation are considerably longer than the average animal. Apocalypse uses the technology attached to his body to shut himself down for hundreds of years at at time. This metabolic suppression ensures that, each times he wakes up, he is more powerful than he was prior to the long rest. This will probably be used to explain why he hasn't encountered characters like Wolverine before in the X-Men movie franchise, in spite of the fact that some of those characters have been alive for a very long time.
