Yeah, Stilly, I've had "volunteer" tomatoes, tomatilloes, cherry trees, a pumpkin and even a watermelon in my yard over the years. Only got one melon from that plant, and it was pretty dinky, though tasty.   My volunteer bing cherries look and taste like the domestic ones, but they're so small it's not really worth dealing with the pits to eat them. (Could maybe boil them down for jelly and separate the seeds from the pulp that way.)

My compost, of course, was the source of my volunteer peach tree too.

And next to that peach tree is a 2-year-old volunteer avocado tree. I'm amazed it survived the last winter in Portland!   I doubt it could ever bear fruit here, even if I grafted cuttings from a fruit-bearing avocado tree onto it, because of the weather, but it it makes it through this next winter, I may try that.