Person A argues that 20-23 are early 20s, 24-26 are mid 20s, 27-29 are late 20s, and that evenly dividing the three ranges makes the most sense. Person B argues that if you are 20 or 21 you would never identify as "early 20s" because our society places special emphasis on age 21, thus those are omitted and that the ranges are 22-24, 25-27, and 28-29. Person B concedes that person A's argument is valid for ages starting with the 30s. Who's right? And a followup question: is person B right about ages 20-21