the musical wiring of my brain
I play hammer dulcimer (well), bodhran (competently), hand drums/tambourines/etc (minimally), and bowed psaltry (basically competent). I had several years of piano lessons as a child, but can't do anything more than very basic stuff now (oops). I used to play appalachian dulcimer a little, but haven't in years. I've played around with harps a little bit, but never learned to play.
I tried to learn folk guitar when I was in high school, but my fingers were too short to chord correctly. (They probably still are, though back then I didn't know that there were guitars with narrow necks for people like me.) I also had trouble wrapping my brain around this "non-linear" instrument; at that point the only instrument I had played was piano, where the notes were nicely in a row from lowest to highest. Of course that's true on a fret board as well, but the parallelism of doing it six times with offsets confused me. Still does, somewhat, though I've played really simple bass lines (electric bass) on a couple songs that On the Mark does. Really simple, though. And I memorized the relevant fret/string positions; if you asked me to find a particular note (that's not an open string) I would have to stop and compute. That gets better with practice, of course, but I find it challenging.
I have played around with recorders a bit, but haven't put the time in to actually achieve competence. I find learning the fingerings to be hard.
The conclusion I draw from all of this is that while I am good with timing and rhythm, I am not so good with fingerings, especially if I have to move several fingers at once in order to change pitch. I think of music "horizontally", not "vertically", and I think of notes as single things that you do, not aggregates of multiple actions. (This horizontal/vertical thing applies to singing, too. I can sing arbitrarily-complex counterpoint, and stand a decent chance of sight-reading it not too badly, but close harmony drives me batty as a singer, as does your stereotypical randomly-jumping-around alto line.) Obviously I can play instruments that use all the fingers, as I was competent on piano lo these many years ago, but I suspect the linear nature of the instrument makes a big difference for me.
If all of this is true, then it should be a predictor of other instruments that would be good, or bad, for me to try. It's a pity that cello or viola da gamba is probably on the "bad" side of that evaluation; I love the sound of deep, rich, bowed strings.