Here's something that bugs me: black holes aren't holes at all! They're regions of space where so much mass is packed into such a small area that nothing, not even light, can escape their gravity. They're more like ultra-dense balls than holes.
What Happens If You Fall In?
Spaghettification. That's not a joke - it's the actual scientific term. The gravity at the event horizon is so strong that you'd be stretched out like spaghetti. Fun!