The classical community says hello!!
I think if the first instrument you picked up didn't have frets, and you just had to learn where the notes are to be in tune, you'd just internalise it.
Actually, I know that's true because my first ever instrument was the trombone, which I can play in tune even after a long break from it. I just know where the positions are and if i'm slightly off i can "fudge it" back into pitch.