Why do people baby me?

My mum babies me and so do other people. When I am cooking or doing anything independently, she looks over me and says ok we can work this out together. I can work it out myself. I am starting to feel as if I am disabled. When I go for an appointment to this employment agency, the lady calls me sweetie and when I say I have an appointment she says "have you" in a baby voice and tells me to take a seat, At the workplace this person asked can I cut a cake up and treats me like a baby. Why do people do this. When I ask a question, people say shhh sweetie and treat me like an idiot. I am 32 years old but look about 23, or so I have been told. I am sick of being treated like this.