There are limits to how much trouble I'd care to invite into my life in the name of having fun. And your example of hang gliding is a good example. Things can Go Wrong (tm) and likely very wrong, but you minimize the chances by knowing what you are doing.

Compare that to zorbing, where you are guaranteed to be doing micro-brain impacts every single trip, and the assumption is your body will repair the damage.

Two very different risk models, and I don't feel the same way about them. Both are fun, and I'm willing to do both, but it feels like I arrived at that conclusion by very different paths, and I'm having a hard time figuring out what the differences are.