Learning Something New Will Give You A Mood Boost, Too
I'm not advocating taking online college classes necessarily. Although if you want to, you absolutely should--why the heck not? I'm advocating education in any form.
So often adults get the vibe they've learned everything they need to know to get by in their day to day lives. That may be true. However, I have found that many of the coolest things I ever done and most of the new innovative ideas I have ever had have come from expanding my circle of knowledge. But don't take my word for it. Many of the most successful people you can think of include ongoing learning as one of the very highest priorities.