Yeah, he definitely optimized on his choice of sport by selecting one of the few where the advantages of age and genetics are minimized.
Anyone's reflexes will decline with age, so Dan's choice is of golf is a good one with respect to his slower reflexes as a potential golf pro in his late 30s, as compared to the reflexes of 20 year old potential golf pros, are not such a big deal.
Of all sports, I think it's fair to say age and genetics are less important in golf than, say, football. bayleo's statement seems fairly accurate to me.