I was 8. It was when I just grew more violent and starting to distrust people partially because of said realization.
At 5, I didn't knew I was the odd one out.
Even as obvious as playing with 7-10 year old street boys on a more dangerous playground on daily basis, instead of other girls of the same age or even think about how or why as to whether or not to be with them. Even after knowing as the only girl who does this and that... Even seeing that I'm not mingling or joining in, even after failing at it.
Even after being bullied -- that's not an enough 'alarm' for me, even after as the one who always have an outburst, even after knowing I'm particularly violent and would wander around, even after being dubbed as a tomboy, even if I was scorned and had anyone point at me in front of the principal, even misnaming several kids at school, even after being rejected, even after being explicitly told that I'm weird.
I was at least THAT emotionally and socially delayed, compensating for something else (PIQ).