I taught my son how to ride a bike when he was seven or eight. The process took all of 15 minutes. He's been skiing since he was 18 months old. We had him as a proficient swimmer by nine (as that took two years).
At thirteen here are things he doesn't know: how a landline phone works, cursive writing (as he doesn't have a signature yet), addressing an envelope to mail, how to knot a tie, and how to set a table for a meal.
But he's a great cook, could probably change the oil in my car, and knows how sports betting lines work, so there is some good parenting to be had.