I picked up my first stringed musical instrument at 45, when I wanted something to do with my hands while I was quitting cigarettes. As soon as I realized how chords, fingerstyles, and the keys of songs worked, I found it easy to just jump in with other people, even when I didn't know the songs. I'm not sure if it is talent or just a systematic pretending to know the songs, ha ha.
But, what amazes me is my wife on the fiddle. It doesn't have frets, and she plays by ear. She can actually jump in with anyone, in any style of music and hang with them. However, if you ask her about keys, notes, or anything about music, she won't have a clue. Those Lunsfords are born with music coursing through their veins.