Why was the clown Mayhew interviewed depressed and why was he a clown?

He would prefer to be a groom or a police officer, anything except a clown. However, now that he had a wife and children to support, he clowned from 8 am to dark every day for 6 shillings per week. Ashamed, he hid his occupation from the neighbors. Often when he was working, all he could think of was that he had two children at home with nothing to eat.