I'd have to agree that the more wrecked machines I recover & the more friends/aquaintances which meet an early demise the more I question the sanity of flying under powerlines or chasing cattle out from under trees. I have recently had a 2 year stint off from flying to get some cash together in a politically & socially unstable country & I don't mind admitting on a few occasions I also had that "what the @#*$ am I doing here" feeling. I've put this feeling down to the evolutionary "fight or flight" instinct, a function designed for self preservation to keep us alert & build up the adrenalin. As the saying goes, we can either be bold or old, but not both. Like some of the previous posters' I have had an experience when the hair stood up on the back of my neck. While surveying powerlines I had an uneasy feeling so I climbed to survey the situation & give myself time to check everything & about 1/2 mile ahead was a long single strand wire across my intended flight path & I know I would not have seen the poles at each end of this span - freaky. As my flying experience built I also came to the conclusion that it was ok to feel "uneasy", as when this happened I found myself checking & double checking guages etc, but if I ever got myself into a situation which caused adrenalin to flow then I had stuffed up severely. Familiarity breeds contempt, fear keeps that contempt in check.
While on this recent jaunt into the 3rd world I also came to the conclusion that if I did have to die(& don't we all) then my first choice is peacefully of old age in the arms of loved ones, second choice in the rolled up wreckage of a helicopter. I do everything humanly possible to eliminate the risks of each flight but accept the fact that at some stage it is possible that won't be enough.