I had a Window’s peak when I was 12, why is that?

I wrote about it here: https://newhair.com/wp-content/uploads/2018/11/phenotype-article-published.pdf If you read the chart on page 318, the widow’s peak (6%) can start in boys ages from 5-10 and 36% in boys 10-15. That means that loss of the juvenile hairline can start early in life, as early as 5 years of age.