I'll second what someone said earlier about survival skills being highly context dependent. Around home... well, I'm from the state with the least remaining native habitat. It's a very different place from wilderness areas where you can hike for days and not see another soul. Which isn't to say you can't get in trouble in Iowa... but help usually isn't too far off.

Much of my knowledge, experience, and training in "worst case scenario" survival situations has been either in the winter (in the northwoods), or in southeast Alaska (would NOT want to have to try to survive an Alaskan winter... but the summer, no problem... and I'd rather get dumped in a southeast Alaskan winter than either of the two situations below). But of course, I'd be relying on fairly basic training and experience, with a side order of logic and creativity, and I'm aware that it would only take me so far.

On the other hand, drop me in the desert and I'd most likely shrivel up and die. I have a few vague ideas about finding water, and what to watch for as far as dangerous animals and terrain... but in reality, I wouldn't be prepared to deal with the situation at all. Fortunately, life rarely takes me to deserts!

Tropical rainforests, now... there again, I'd be completely screwed if I somehow found myself off-trail without my pack. But honestly, a good part of the reason I'd die if I were lost in the tropical rainforest is mental. One of the most important things to do in an emergency is stay calm and think things through... and I don't stay calm well in the jungle. It's the heat, the humidity, and the ants.