For context, I shot a 79 (round of my life) when I was 18. I had unlimited golf for the summer on a dirt cheap junior membership, so I played pretty much every day and brought my score down like 20 strokes.
If you do something regularly at that age, I think it's much faster and easier to get good than as an adult. Especially if you have high athletic ability in the first place, which he obviously does as an athlete.
I hope his intelligence translates into aggressively pursuing areas where he needs to improve. Could be a very special player for us.