How long it takes to learn popular jobs in AmericaIn the Middle Ages, people attained expertise in their trades through decade-long apprenticeships at the feet of masters. Let's say the combination ofcollege classes and internships is our modern, if decidedly less romantic, analog. For anyone who has spent an unpaid semester fetching coffee and making copies, such grunt work can seem pointless. Yet just like those young squires or aspiring blacksmiths of centuries past, interns and students should take solace in knowing that expertise takes time.Here's a look at some of the more skill-intensive jobs in America, and approximately how long it takes to prepare for them. Keep in mind that, as Malcolm Gladwell writes in his book Outliers, it probably takes about 10,000 hours (that's 10 hours a day, every day for two years and 270 days) to become an expert at anything. Be sure to tack that onto any figure you see below.College Professor (Humanities) Nine years: four as an undergrad, three years of graduate course work, two years (minimum) working on a dissertation.Architect Eight or more years: It varies, depending on the level of the degree, but you're looking at up to five years for a B.A. in architecture, three years of internships and work experience, including close to a year of preparing for exams (aspiring architects spend nearly 30 hours just taking those tests).Aerospace Engineer (A.K.A. Rocket Scientist) Four to five years of school, but that could easily climb up to seven or 10 with graduate or postgraduate studies.Elementary or High School Teacher Five or more years: After getting a B.A., credentials programs take one or two years.Police Officer Three to four years: many require a couple of years of college or relevant work experience, six months or more in the academy, and three months of field training.Neurosurgeon Fourteen or more years: four years of undergrad, four years of medical school, one year of surgical internship, and five or more years in a neurosurgical residency.Commercial-Airline Pilot Four or more years: an undergrad degree plus 250 hours of flight training, though you probably need closer to 3,000 hours of flight time to get hired by a commercial airline.Psychiatrist Twelve years: four as an undergrad, four as a med student, and four in residency.Head Chef at a Prominent Restaurant Three to six years: one to three years in culinary school, two or more years of apprenticeship.Yoga Instructor Two hundred to 500 hours for certification.Investment Banker Six years: four as an undergrad, two as an MBA, and a lot of time at the office afterward.CIA Agent A minimum of six and a half years: four years of undergrad, two years of background check, six months to a year of training (additional years of military experience will help).Military General It varies, but it's going to be faster during wartime.President At least 35 years.