I'm finding harder than anything else that I have tried. They say you can't teach an old dog new tricks, but I don't believe that one.I guess I'm just very slow or something. I find learning on your own is very hard, but I keep plugging at it.
I have never learnt to play an instrument as a child, or as an adult. I don't know why it would be harder for an adult. It takes training and practice just like it does for a child. I have come to greatly admire piano playing, so if anything, that's what I would like to do.