I have played piano since I was in first grade and took bona fide lessons through high school... Then my natural tendency to improvise rather than practicing led me in other directions. I sight-read very well and play regularly [without using music, I play by ear] with a worship team at church; sometimes we do coffee shop things on the fly, covering benign secular songs from the 70's and 80's and up, that's a lot of fun. I have the ability and talent to go pro, probably, if I wanted to dedicate the time to do so (it would mean a few hours of practice a day and just listening and emulating lots of different music, to build up my mental riff/pattern library), but I have too many responsibilities and not enough desire to put in that much time right now.
In school, I "officially" played clarinet, oboe, and xylophone. Musical instruments were not too hard for me intuitively, it's the practice part that always got in my way -- much of the skill comes from repetition and integrating body and mind together, laying down the physical/kinetic memory as well as maintaining finger or lip strength (to name two).
The one instrument I wish I could play is acoustic guitar, and I guess I could learn it, but it's very different mentally than the piano and demands a lot more coordination from my left hand (for fingering purposes)... if you start a string instrument when young (before age 12), your brain will allocate extra memory/processing area to the left hand, but as an adult you have to work with what you have.