Advantages of being older for your grade

The Malcolm Gladwell book “Outliers” describes how being older, even by 6 months, compared to your peers in your youth, drastically changed your trajectory in life.  He described the roster of a Canadian youth hockey all star team and noticed the majority of the players had birthdays in the first half of the calendar year.  I feel it is a book about parenting for people from more modest backgrounds (how the wealthy game the system), since by the time you read the book, it’s probably too late to help you much.  Imagine starting 10,000 hours of some hobby other than work in your 20’s.  You should probably start in your youth.
 

I was one of youngest in my grade, and felt for sports, maturity, leadership, and intellectual ability - I might have benefited from being a grade younger.  Thus, I was a “late bloomer” in college as opposed to high school.
 

My son, on the other hand, is one of the oldest in his kindergarten class, and I can tell that his physical maturity, confidence, humor, and the fact his older sister is at the same school, he has several advantages.  Plus, he’s really comfortable around girls and they like him. 
 

I’m wondering if you felt your trajectory changed because of your age relative to your grade.  Whether you were younger or older.  And what techniques or strategies did you have to overcome or enhance.  
 

Ultimately, I did not have “outlier” talent, so even if I was older in high school sports, I wouldn’t have been at state champion level.  And over time, the benefits fade.  Raising happy children is a priority, but also I’d want them to have advantages if I can provide. What really helped you?