I'm 35 years old and people presume I'm in my mid 20's as I look young. Colleagues think I'm younger and clients think I'm younger.
I don't think anyone knows how to act their age you just go by everyone else. I think personally I act younger without meaning to do so. Especially cause I have no peers bar my Twin. My Twin on the other hand is roughly our age. She acts older than me.
I feel like a fraud