Ray Allen has retired from the NBA after 18 seasons and winning two championship rings.

The 10-time All-Star, 41, announced his retirement via the Players' Tribune, penning a letter to his 13-year-old self about perseverance and practicing hard, not worrying about fitting in.

"What I want you to do is this: Go to the basketball court. Stay at the basketball court. You can build your entire existence there," Allen wrote.

Allen's career saw him represent the Milwaukee Bucks, Seattle SuperSonics, Boston Celtics and Miami Heat. He was part of championship teams in Boston and Miami.

He has not played since 2014, but Allen amassed 2,973 three-pointers, the league record. Stephen Curry is still more than 1,300 three-pointers from that mark.

"On behalf of the NBA family, I want to thank him for being a wonderful ambassador for the game," said the league's commissioner, Adam Silver.

Despite the championships and records, Allen told his younger self that highs are temporary, but the daily work is what makes it all worthwhile.

His letter continued: "I really mean it from the bottom of my heart: Life is about the journey, not the destination. And that journey will change you as a person."