Physicist here. Imagine a fish swimming down a river. Down the river, there is a water fall, with water falling faster than the fish can swim. Past the point where the water is falling faster than the fish can swim, the fish can not turn back and swim up the waterfall, back into the upper part of the river.

The same thing happens in spacetime. As you get passed the event horizon, there is no way to move through spacetime so as to emerge back through it.