How many years do to become a pediatrician?

Considering that there is about 13 years of college required to become a MD Pediatrician, if one started college at age 18, then that person would be 31 before they graduated medical school. It would be impossible to have your MD license and practicing pediatric medicine at, say, age 21. The right to become a pediatrician is not based upon a minimal age, rather based upon years of education and residency completed.