Well, I know a very unusual guy who was a licensed CPA at age 21 back in March of 1974 but who had a very odd career path. He finished his undergrad degree in accounting (3.79 GPA, I think) in three years out of high school and got his MBA in the fourth year, all on full academic scholarships (not based on financial need and yet paid all of his college costs – tuition, room, board, books and then gave him an additional $3,000 for spending money). Yet even with the free-ride, he worked 25 hours a week for two college years at Haskins & Sells (one of the Big 8 back then) while in college. He passed the CPA exam on his first try, with the highest scores (sorry, I don't know what they were) in his Becker CPA review course class of over 100 students. He had easily met the 120 hour credit requirement back then as well as the 2,000 hour work requirement as he was finishing up his MBA and was given a CPA license at age 21. Then he gets asked to be a Becker CPA Review Course Instructor at age 22 (at compensation rates paid to managers), starting the week after he got his MBA and a week before he started with Coopers & Lybrand now PwC. And at Coopers, his first job is on a major fraud audit with a staff of 20 and he (the new kid) is the audit team's expert in statistical sampling.
The guy was named The Outstanding Senior Man of the University's class of 1973, not because of his academic accomplishments but because he was this super nice, well-organized “good” guy who was the volunteer Director of the Campus Volunteer Center in '71-'72 when the club grew six-fold to become the second largest “club” on campus. He was not only the Director of these 240 volunteers working weekly for twelve different great causes, his volunteer job was the midnight to 6a.m. Saturday morning shift on the Campus Help Line. He was engaged at age 19 to a very bright young lady who became a well-respected attorney. At the request of her mom, the marriage was postponed for over a year. So, here's the question: How old was this “superstar” when he became a partner? Hint: He was with Coopers & Lybrand, later PwC for 26 years. Answer: He never became a partner (well, he was “acting partner” on a few engagements, but never was an official partner or principal). In fact, he never got to go through the partner process nor even attend audit manager school, despite being a manager in 1979, and then a director in 1980 and senior national/global director for most of his 26 years at the firm. However, after he quit PwC at age 47, he became a well-paid CFO of two very successful public companies and became a multi-millionaire in his fifties and retired early. All things considered, his CPA career was quite rewarding even though he never made partner.