Actually, you can. At the university level, you can go in undeclared, try a few things with your general education, and decide once you've found something you like. The downside, of course, is the cost, but there's funding available. There are some wealthy members of the Blackpoint community who might be willing to help as well.
If you're not quite at the university level and need to acquire a GED first, you can still take classes to discover what you might like in the meantime. There are options online for free courses in a wide array of subjects, though that's not quite the same as face-to-face learning. If you have some specific ideas in mind on what you might like to learn, I might be able to help you. I ran an academy for young women for many years before I was pulled back through the portal. And if I can't teach it myself, I can track down someone who can.