Nope!
I actually started myself. I bought a foreclosed home and fixed it up on the weekends. I still had a job elsewhere at the time. When I finally did sell it, that is when I began house flipping. Buying up cheap properties, fixing them up, and selling them.
My father mentored me in a sense. He was a skilled house flipper and made our family a lot of money. I got to see some really cool properties and help when I was younger. I ended up getting my real estate license when I was 23 and started my own business at 25.