I got held back because of my birthday. I started preschool when I was 3 (going on 4). I was already reading at this time. However, there was some rule that you had to be 5 by a certain time, so I had to go through preschool for another year. So I was 5 when I entered kindergarten, and I turned 6 in January of the following year. What fukked me up is, there were some kids who were only like 2 months older than me, but a grade ahead. There was this one girl in my graduating class who was born the same month as me and her bday was a week after mine...but she was a whole year younger than me.