When you look back, at what age do you feel like you became mature and sensible enough like a normal person?

When my daughter was going to start kindergarten, I thought about how she had no siblings, and she was about to be surrounded by other kids, who were going to call her names. It's what kids do. So I would call her the same sort of tame things that little kids say, but I did it while I gave her a hug or gave her something to eat. Then, one day, all of the adults were waiting for their kids to be released to them, individually. When my daughter approached me, I said 'hey, boogerhead!' And every other adult went silent and glared at me. So I felt bad and wondered if I was doing the wrong thing, and I quit with the nicknames. A few days later, she said, "Are you mad at me? You still love me, right?" And then we talked and she thought I didn't love her anymore because I hadn't called her the silly nicknames. So I felt like my heart had been thoroughly curb-stomped.