After 18 seasons, Ray Allen has officially announced his retirement from the NBA in a letter to his younger self for The Players Tribune on Tuesday (Nov. 1).

In the heartfelt letter, Allen details his upbringing as a military brat and his playing years at UConn. He then goes to write about the sacrifices he had to make to stay successful in the NBA before stating that he is done with basketball for good.

"I write this to you today as a 41-year-old man who is retiring from the game. I write to you as a man who is completely at peace with himself," it reads.

"The hell you experience when you get off that bus will be temporary," he later writes. "Basketball will take you far away from that school yard. You will become far more than just a basketball player. You’ll get to act in movies. You’ll travel the world. You will become a husband, and the father of five amazing children."

Allen exits the game as a 10-time All-Star over a career spent with four different NBA teams -- the Heat, Celtics, SuperSonics and Bucks. The b-baller also won two NBA championships -- one with Boston in 2008 and the other with Miami in 2013. He is also the league's all-time leader with 2,973 career 3-pointers made, 413 more than anyone else to date.

Fans' reactions to Allen's retirement was bittersweet as they saluted the 3-point clutch king for an amazing career on the court.

"Ray Allen; great career, HOF-er, best pure shooter, and a great player for the Celtics. But don't need his number retired in Boston," tweeted one fan. Another commenter wrote, "One of my all time favs Ray Allen officially retires from the NBA. I loved watching him on the 05' Sonics & '08 Celtics. Absolute Legend."

Check out the rest of the reactions below.

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