The concept of a "risk thermostat" is interesting -- people seem inclined to maintain a more or less constant level of risk. I've noticed an effect that interacts with that: my risk inclination seems to have some initial static friction that changes to a lower level of kinetic friction once I'm moving. Example: some years ago I was feeling a little hesitant to try snowboarding because it seemed "risky" (I knew I'd fall a lot). The first time I tried it, I was having so much fun that I pushed myself well into exhaustion and took some crazy tumbles that didn't stop me from getting up and riding more. I suppose my initial response might just have been an underestimation of the "reward" part, rather than an incorrect estimation of the "risk" part.