Why did Bjorn Borg retire so early?

Former world No. 1 Bjorn Rune Borg was a Swedish professional tennis player. He became the first man in the Open Era to win 11 major singles titles, including five consecutive Wimbledon Open (1976-80) and six French Open titles. Between 1977 - 1981, Borg held the No. 1 ranking in singles for a total of 109 weeks. He is the only male player to achieve the Channel Slam thrice and is considered by many as one of the greatest players of all time. Borg won 66 ATP singles titles in total, including back-to-back Tour finals in 1979 and 1980 and the WCT Finals in 1976.

He was inducted in the International Hall of Fame in 1987 and won several awards such as the ATP Player of the Year, ITF World Champion, and BBC Sports Personality of the Year Overseas award.

Why did Borg retire at 26?

Borg left his professional tennis career abruptly at age 26 as he wanted to have a private life away from tennis. The decision came as a shock to the entire tennis fraternity. Fellow companion and rival McEnroe tried his best to persuade Borg to continue. Borg's first wife and tennis professional, Mariana Simionescu, shared that he was a calm and composed person until he lost a match. In an interview with the New York Times, he shared that he was happy with his retirement decision as he had stopped enjoying the game.

Borg felt that if a person is not happy after hitting every shot, it's very difficult to continue to play. In an interview, Borg said that today's generation players have more security. If he had that kind of security, he would have played many more years without worry.