Take a Personal Finance Class
One big issue many people face today is that they do not know how to handle their money. How many people leave high school, or even college, know how to invest for retirement, obtain and pay a mortgage or even save for a rainy day. To often, people are living paycheck to paycheck. The secret to getting rich, though, is often that it takes a lot of time. The sooner you start investing in retirement, the more time it has to grow. The sooner you learn to save, the more money you will have when it comes time that you need it. Learn to handle finances when you are young, and it will benefit you throughout the rest of your life.
Take a Social Dance Class
Dancing is a great form of exercise. It also developed coordination and balance. But the main reason why I recommend taking a social dance class is for the social aspect of it. In social dance you are required to dance with a partner, and often many different partners. So you have to learn to approach someone you don't know, and learn how to socialize with someone for at least the duration of a song. It also teaches proper etiquette, which is also a good thing.
Be Part of a Team
When I say be part of a team, I'm not referring to just sports. This may also be a club, or some other group. Anything from a book club to choir to basketball. Being part of a team teaches cooperation. You have to learn to interact with others and socialize. It often times requires dedication, and being a good team mate also means responsibility. People will often rely on you to do your part, and this will help you grow.
Have Meaningful Conversations With Your Parents and Other Adults
These guys have something that you don't...experience. they also see things differently then you do. There is a lot to learn here. Their experience may not be the same as yours, but if you are smart, you can always get a few good things you can apply to your life. And besides, a lot of elderly people love the opportunity to share their knowledge.
Find Something That You Have a Strong Opinion On, and Study the Other Side
The big point I must emphasis here is that you study the opposite side not looking to prove them wrong, but rather to gain understanding. This isn't about changing your mind, or the minds of others, but rather about developing love and compassion for everyone. These days, people separate themselves to much. We need to find out where we agree and use that as a foundation to build our love. Not everyone who opposes gay marriage is a homophobic bigot, and not everyone who supports it is a godless pervert. Learn why you believe what you believe, and learn why others believe the other way. It will develop your love for you fellow man.
Attend a Worship Service or Activity Outside Your Own Beliefs
Once again, this is about developing love here. Learn what others believe and learn it from the right sources. You will feel a greater connection to others. My wife and I attended a special Jewish cooking class once, and it was fascinating. I've also sat in on prayer services for other churches than the one I attend. I didn't agree with everything they taught, but I could still learn from their love and devotion.
Take Time to Think
We live in a world full of distractions. People don't like being bored, and now we have the technology to keep us distracted all the time. The problem, is that too often we don't give ourselves time to sit and think about things. Take time to have a meaningful conversation with yourself and evaluate your life. Make goals for improvement (beyond just losing weight) and find ways to improve. Accomplishment can bring great satisfaction.