Every thing begins with an idea. I have always wanted to play jazz piano, and now I am doing it, albeit at a lowish level. I see no possibility of getting worse with practice. There will be a plateau or two, with steady progress between the plateaux, and then a point at which I won't get better.
It strikes me that the key with these kinds of things is neither to underestimate nor to overestimate the difficulty of it. If you think it is going to be easy, then it is easy to get frustrated. If you think of it is impossible, then you won't even imagine doing it. My approach is just to get lost in it when I am doing it. I could spend 15 minutes trying out variations of a few chords. The other day I closed my eyes and I could still play some of my songs fine.
Most things, you can probably do. Ride a bike, make ceramics, or grow plants. If you are interested enough in it, that is. I am quite sure that I could be a crossword puzzle constructor. Some day I'll want to do this, though not now.