Music and families

I've taken to reading what appear to be extended obituaries in the morning paper. The "Region" section of our paper does longer stories once or twice a week about some fairly ordinary person who's just passed away. They're really charming stories that often reveal some interesting personal history, e.g. Aunt Edna moved here from Romania and bought a ranch in Sonoita, or my dad invented peanut butter, or uncle Fred owned a little store where kids could get snowcones for free, etc.

Anyway, I found one the other day about a guy who was described as an incredible guitarist, but who had never taken a lesson. On reading the story, it turned out that i) he really was an incredible guitarist, and ii) that both of his parents were guitarists and that when he was a kid both parents would routinely pull out their guitars for the evening.

Not to detract anything from the guy in question--who really seems to have been an incredible guitarist and an all-around nice person---but I'm wondering how much variation there is in terms of "music in the home". While the person in question may never had had any formal instruction, it seems like he had almost daily exposure to guitar playing by several family members.

I think my experience is probably pretty close to the norm for most Americans. My siblings and I all had music lessons of various sorts, but our training and playing lasted only a few years. Neither of our parents played anything, though both had had similar upbringings. (My parents are divorced, but I think that's orthogonal.)

So the general question: how much variation on musical "exposure" is there and does that play a role in whether kids pursue music?

The specific question for me: can I honestly expect to make serious progress on the guitar when I did not have extended childhood or current exposure and am no longer taking lessons?