Once they become big enough, players start to be recognized by a lot of factors other than their names. Nicknames, signature moves, and of course, jersey numbers become synonymous with the best in the NBA. And nobody comes close to Michael Jordan in terms of fame and popularity at their basketball peak. MJ's jump became iconic, so there's no doubting the fact that No. 23 was always going to be associated with him.
Considering that 23 is a pretty random number though, there has always been curiosity regarding why MJ would choose to wear it. And it's not the only number he's worn in his career either, when he came back from his first retirement, Jordan wore No. 45 for a while before switching back to No. 23. He explained the reasoning behind his choice in a short documentary during he went to several prominent European cities.
(Jordan's explanation starts at 4:37 minutes)
"My brother wore No. 45 which was my number. So when we was on the same team, we couldn't wear the same number. So I chose half of what his jersey was, which was 22.5, which I would rather have 23."
MJ learned a lot from his brothers, something he spoke about in the Last Dance documentary. His older brother Larry also played basketball at the collegiate level although he never did quite make it professionally. It's no surprise that Michael Jordan would want to have a number similar to his brother, the Chicago Bulls icon got his single-minded determination thanks to him.
And whatever his reason was behind picking it, he surely made the No. 23 one of the most popular jersey numbers in the history of sports. Most people that see it will always think of Michael Jordan and the greatness he achieved wearing it. And those that wear the number for other franchises will always feel the weight of what it signifies.