Why are adult jokes more brutal than kid jokes?

My family was picking on me on my birthday but I’m only 18. I don’t mind joking but it’s exhausting and it’s tiring to me.
My told my sister that dad called me old woman but she said, “You know how dad is. He just picks on people for fun. You should know. You’re been around sarcasm and teasing. Stop tripping and just laughed it off.”