To stay alive we have to be curious. Some people are very curious about something that it eventually becomes their passion. I love to learn something new whenever I can. If you go to the library near you, you will find lots of things and subjects that are interesting. Photography, a new language, history, culture, science... are just some of the things we can explore. The best thing about this is that we are not studying because there is an exam or test coming up soon, it is because we simply want to know. That's what makes it fun and enjoyable. I went to a music college some years ago because I could not sleep until I had a clear idea about...for example, what dorian scales are and how composers used them, what chromatic approach chords and sub Vs are etc...By the way, harmony is still my favourite up to this day.
On the other hand, we could learn something that we had never done before, like cooking :) or some sports..
