Becoming an anesthesiologist means you'll be spending the bulk of your 20s in school, when many of your friends may be out in the world carousing and setting the stage for the future ailments (cirrhosis, addiction, bad hearts and obesity) that will keep you employed once you hit the workforce as a doctor. Typically, it takes from 11 to 16 years to complete a medical education: four years of undergrad, four years of medical school, and anywhere from four to five years of a residency in anesthesiology. And the book learning doesn't end with the residency. To keep your medical license, you have to keep on taking continuing education classes and learn about razzle-dazzle new techniques.
You may be smart as a whip, but to practice as a doc, you must pass licensing exams, like the U.S. Medical Licensing Examination.