My brain is just kinda hurting by the concept that something which causes gravity is the very thing that prevents gravity escaping it. I get stuck in this circular self-referential loop, which basically means I don't understand it.

If anyone who doesn't do tensor calculus tells you they understand General Relativity, they are simply incorrect. So, don't sweat it. Grokking in fullness requires heavy math that not everyone gets exposed to.

The point shawn is making is an issue if you only look at gravity as a particle or a wave - the typical quantum mechanical view. But, as we know, QM and Relativity don't get on so well. And, back in classical mechanics, there's a

*third* thing gravity is - spacetime curvature.

General Relativity is all about calculating that spacetime curvature. And, it

*does not care* about the whole particle/wave thing. From this viewpoint, there is nothing traveling from within the hole to the outside world, so the speed with which it does so is irrelevant.