What you should learn in your 20s in order to to avoid pain in 50s.

The most important choice in your twenties is to decide where to go and with whom. That means, most importantly, determine WHAT you want to do. And make the necessary steps in this direction. When a person is not burdened with a family and children, he or she has the right and must invest time and knowledge in him or herself. The WORST THING you can do in your twenties is to waste your health immensely on alcohol or other rampant fun. Your body won't forgive that at fifty. You should learn to communicate with people, how to say 'no,' and stay open-minded at the same time. Set goals and priorities, and be able to uphold them. It's very important to learn to handle money, and build financial goals and priorities in your twenties. Do it at 20, and you will be immensely grateful to yourself some time later.