Young people are reckless.
It doesn’t matter if you’re part of the current generation Y or if you are a millennial, or if you are a baby boomer reminiscing about the days you did LSD. Part of being young is about experimenting, testing your limits, and seeing for yourself. Young people are less risk averse than older people, but probably because older people have been there, done that, and they have too much on the line (e.g. a family to raise, a caring spouse, a mortgage payment etc!).
Young people take risks without thinking about the consequences, either due to being over confident, or just plain arrogance.