I will start with the question, in case you don't want to read this whole thing: am I the only one who finds most topics interesting when I think about learning about them, but I'm never interested enough to continue studying it after the short online course is over?
After I finish my Intro to Psychology, Chemistry and Physics this month I think I'll start Intro to Biology and Astronomy. I should probably pick something else, or I might try getting the courage to look for a part time job. I had in mind buying an organ and learn how to play it, but I feel bad when there's one in my sister's room (she doesn't know where the transformer is, and since my grandma is sleeping there I don't want to go look around for it, so I can't play it). Another option is brushing up on maths since there's a lot of it that I just learned for exams and then totally forgot.
Other options that I have in my mind are learning how to draw, ceramics (don't see how though, no idea about materials and stuff like that, probably can't even do at home), cooking and marine science. If you have any other suggestions, go ahead.