I found out that I really love birds. I've loved birds all my life. I put out some feeders on my balcony, and watched the various birds that came to feed. I am also a lover of photography, so they are a wonderful mix. I am going to join the Audubon society as a full member when I have the money. I would have never known about this unless I watched my surroundings. I do have a job, but I don't have any friends willing to just hang out anytime without some huge plan, which I rarely do. I don't have kids, or pets, so after work, I just never know what to do.
Try looking outside. If you see a nice trail nearby, try walking. If you have open areas to plant a garden, do that (though now it would be more of just getting it ready for next year). Use your surroundings and maybe even your past to dig up any hobbies that you may have forgotten you loved.
Best of luck.