I have been experiencing the same. A few factors I can think of. Exposure -- As kids, we aren't exposed to consequences of accidents, blood, etc. So because we

I have been experiencing the same. A few factors I can think of. Exposure -- As kids, we aren't exposed to consequences of accidents, blood, etc. So because we have 'seen' less of it, we believe it cannot happen to us. Responsibilities -- I believe the 'responsibility' factor kicks in as we age. When we are kids, we are for ourselves so we end up taking more risks. As we get older, get married, have kids, watch our parents getting older, we start caring more for security as life seems to be important because of our dependents. We are adults for majority part of our lifetime so as we grow older we only become habituated to remain careful about our life.