Leaving the Nest

I had a talk with a co-worker today about when is the best time to leave home and be on your own. She is of a different culture than my own and wondered why I live alone and outside of my parents house. I told her that I needed to grow and that there can often be conflict in the house when their are multiple adults, especially if there are multiple men in the house. However, she felt that many lessons could be learn and financially people can do better if they stay at home longer. I told her that some lessons can be learned through experience and having to make decisions without parents being their to monitor and at times make the decisions for us. I also communicated to her that I believe some mistakes need to be made in order for growing to be accomplished. Parents won't be around forever or all the time, so what happens when they aren't around and decisions have to be made? So my question is when is the best time for someone to move out? What age range would you say is the best time? What lessons should be taught to someone before he/she leaves home?