I'm sure heredity is part of the picture, but I feel it's a complex interplay between genetics and environment - there was a huge argument some years ago among scientists and early-education teachers and theorists about whether it was "nature" or "nurture" that mostly affected childhood development; they seem to have come to the common-sense conclusion, "both."
This is how I see it. Most newborn children come fully equipped with what I call the Questing Gene (which probably isn't exactly a "gene" as such, but it's a useful shorthand). Young children are interested in everything. Kids learn language and motor skills at a phenomenal rate in their first two or three years, constantly picking things up, sticking their fingers in things, taking things apart, asking all kinds of questions and driving their parents bonkers. If they're lucky their parents, siblings, relatives and friends encourage this insatiable curiosity with books, storytelling, music, art, whatever.... if they're unlucky it's a matter of "Don't bother me, I'm busy", or "We don't do that" or "Don't ask stupid questions" - or, perhaps worst of all, "Don't be stupid, you can't do that."
It takes a very, very strong-minded kid to survive that kind of squelching, and most seem to be thoroughly conditioned into accepting whatever they're told by about the age of five. Behaviour, religious and political views, opinions regarding scientific and artistic and philosophical questions, become solidified into dogma, which it is very difficult, even impossible, to break free from.
Those of us who were lucky, or strong-minded, as young children, survive into adulthood with the Questing Gene intact, always wanting to know more, experience more, see what lies over the distant hills or across the far ocean; some, a resilient few, manage to break free of their early conditioning in adulthood; all of these are the ones who become creative artists, real scientists, explorers, designers, musicians, craftspeople - and, of course, occultists and Witches.
So, altogether, very much a matter of luck, it would seem. The moral of this story seems to be - choose the right family to be born into.
Blessed Be all you Questers out there. keep learning; ask questions, even stupid-sounding ones; shine a light into dark corners and see what scuttles out; turn over rocks and see what wriggles. Explore; read, read, read, whether scientific journals or "Wicca for Dummies"(!) or ancient eldritch lore from mouldering old tomes. And create! Whatever it is! Poetry, paintings, knitting, blacksmithing, spells, rituals......