Here's my answer:
I'm going to start on a tangent, so bear with me here.
Are you curious about food? Like, maybe you read a menu and go, "Oooh! I want to try that! And that looks so good too! And that!" Or you go to a grocery store you've never been to and end up with a month's supply of food because everything looks so good? Maybe you read an article in a newspaper or a magazine, like, one about different kinds of salt, and go, "I want to try every one of those!" Or a new way to make chocolate cake, and think, "I've never tried it that way, but that sounds really good!"
That's how I think about workouts. Like, maybe you don't like just spinning the wheels of your exercise bike. I think of that like raw, washed, plain spinach. I have some friends who can do the exercise bike thing, and some who really enjoy plain spinach. I can't do either. And if spinning the wheels of an exercise bike is like raw spinach, some spinning classes are like spinach fried in bacon grease. There's a heck of a lot of ways you can rock an exercise bike-- just like there's a heck of a lot of really delicious things you can do with spinach!
If I take a class and it bores me, or if I plain don't like it, or can't handle it, I'm not sad, any more than I am when I try a yummy-sounding recipe or dish in a restaurant and it turns out kinda blah. It's probably just not your thing. Or maybe it's not your thing just yet, or maybe you don't like the instructor. Whatever. There are as many kinds of workouts as there are kinds of food-- you can't ever stop learning about them, or get tired.
Have you ever felt that weird feeling deep in your belly when you do Pilates? And felt like you were standing about three inches taller after the class? Or the blissed-out relax after a tough yoga class? How about splashing around in the pool-- with some air-filled dumbbells? See how much you could push your muscles on the weight machines, and enjoyed that rich sensation as you really worked them? Or the loose fluidity of Tai Ch'i? Found muscles you never knew about during a bellydance class? Maybe you like the scenery of biking through a mountain path?
My point is not just that there are lots of different kinds of workouts and there might be one you like. My point is, you can see the different body traditions of the world kind of like different kinds of food. Or different books, for that matter. Just like you can be like, "Ooh, that Shanghai-style braised pork belly sounds so delicious," you can say, "Ooh, Tai Ch'i sounds interesting." Trying the pork belly once doesn't mean that you must cook it every day for the rest of your life-- but if you like it, you've got another awesome dish you'll always be able to turn to. It's not a "I hope this one will finally work with me,"-- it's more like "I wonder what this one will be like?" You don't have to commit to anything, and you don't have to pick one. If you're not trying to slim down, all the better: you can just enjoy the workouts for the fun of it!