My mother is always horrified by the bizarre things my kids do IronMom! I'm one of 4 GTs, and she says all of us put together didn't equal the work of one of my children LOL. I guess DH and my parents are sort of sensitized to it, too (by this I mean not shocked anymore). DS walked unassisted by 8mos and DD by 9mos but both were VERY mobile way before we got to that point... Now I'm pretty sure they are both looking to join a circus - DD is turning a somersault to the splits, and DS is saying that if he gets enough practice in, he'll be great on the high-wire!
Yes, I believe you're right about their somewhat short-sighted realization of danger. We basically have a period each day now, where we go through the 'correct' or least dangerous way to any number of things (that children of their age shouldn't be doing IMHO), so at least if/when they find themselves in that situation, I've covered bases as best I can. Today's for DS3 was when/why it would actually be appropriate to undo screws on electrical equipment, and how to do it safely.
I often question how best to deal with my little bundles of energy - I really wish I had a manual!