Yes, I am an only child.
Iāve never felt normal either. When I was a kid I always felt more comfortable around adults and less comfortable around children my age, which is apparently a common characteristic. Maybe itās because as an only child, youāre less constantly āexposedā to other children of a similar age since you donāt live with any, compared to the overwhelming majority of kids who do? It might explain why I was very, very shy at school and felt less āwith itā than everyone else (and why early secondary school was so intensely horrible).
Socially itās shit, and Iād say it has messed me up. On the other hand itās a luxury because the resources and attention of your parents isnāt divided and you never have to share anything. Definitely worth it overall.