I get quite tense while flying, mainly because I am always waiting for something to go wrong or to discover some terrible mistake I've made!
Funnily enough (and, trust me, I'm frantically knocking on wood at this point), I think I might actually be more relaxed if I had had to deal with something like a forced landing as I would know (hopefully) that I could handle it...
Might be twisted logic that, though
Hersh