Well, it HAS TO BE enough, hasn't it? Considering the alternatives....

I recommend Laurence Gonzales' book "Deep survival". It deals with the key components that all those that survive impossible odds have in common. The book deals with mental processes and how survival is a very thin balancing act to keep the powerful emotions from running the show (thrashing wildly through the bush, giving up in despair and so on). It certainly was an eye opener for me.

That being said, even the top supreme survivalist will fail when the conditions are too tough. Nature does not grant you diplomatic immunity to hazards or environmental conditions. Normally I would at this point digress into a long explanation of that's why we carry those extra layers of protection (i.e. our PSK), but we all know that drill... Stay on topic!

I'd say that the ability to stay rational, consider all the alternatives and actively improving your situation. Improvisation is the logical conclusion of staying open to your surroundings and looking for ways to improve your situation - without the restraint of convention. Hm... look, here's a XXX. How weird. Hm... I could actually use it to do YYY.

Actually, I'd rate improvisation skills pretty high on skills important to survival. And... do cheat: Improvisation is a whole lot easier if you carry some improvisation grease (your PSK). And practice. Someone said that improvisation was just the result of hours and years of practice... He was talking about actors able to improvise off the script, but the point has some survival merits as well.