I don't really have any hobbies at all, and I wouldn't know how to cultivate them if I did. I understand that part of getting and enjoying hobbies is trying new things and spending time on the stand-out activities, but it will be at least a month before I'm able to spend some serious time on doing such things, so I'm looking at a deeper idea of fun, so let me explain a bit about what I understand to be fun.
I spent a lot of my time in my childhood as many young boys do, engrossed in video games. Gaming was my "hobby" and I joined groups and lead groups of adults to at least some achievement in that world. It seemed fun at the time. As I've gotten older it has rapidly lost its appeal, and the gaming I do now is done exactly as an escape. Gaming isn't fun, it's just better than my current situation.
Similarly, my outings with nearly life-long friends, have changed over the last few years as well. Formerly I enjoyed heated discussion and the respect I got from my peers. Now I am more affected by my self-doubt and my friend-group has gotten smaller, losing the people with whom I had the most vigorous conversations.
After a gaming session or good outing with friends I had a lasting satisfaction from the events that had unfolded that night. This lasting satisfaction is what I've noticed to be missing. The actions remain adequately distracting in the moment, but they are not as fun because I've lost my rigorousness in my approach to them. With this gone, not only do I return to my previous emotional state when the activity ends, but the "high" of fun during the activity isn't so high any more.