Gilbert Arenas was born on January 6, 1982 in Tampa, Florida. His father played college football at the University of Miami. In 1984, the pair moved to Los Angeles, California where Gilbert's father was an actor in commercials and soap operas.

When Gilbert was about 11, he started playing basketball instead of football. By the time Gilbert was 14, he was already the best player on Ulysses S. Grant High School in Van Nuys, California (near Los Angeles). During his high school career, Gilbert was named to the Los Angeles All-City team three times. As a junior at Grant High School, he averaged nearly 30 points per game. By the time he was 16 years old, Gilbert has already committed to play basketball at the University of Arizona. His first choice, UCLA (University of California at Los Angeles), had passed on him. During his senior year, Gilbert averaged 33.4 points and 8.0 rebounds per game.

Gilbert immediately became a star point guard at Arizona. He decided to wear the number "0" because people told him he would get "zero playing time".During his freshman year, he scored 20 points in his first game against UCLA. He finished his freshman year with an average of 15.3 points per game. Arizona entered the NCAA tournament as a number one seed, despite the fact that many of their star players were injured. After defeating Jackson State, Arizona lost to Wisconsin 66-59. In 1997, during his sophomore year, Gilbert led Arizona to a final four appearance in the NCAA tournament against Duke University. Duke ultimately prevailed 82-72.

After his sophomore year, Gilbert decided to enter the NBA draft. Many coaches thought that Gilbert was not ready. As a result, he was drafted a disappointing 31st overall by the Golden State Warriors. Gilbert worked hard at Golden State, despite the fact his coach kept him on the bench for much of the season. When he finally got his chance, Gilbert averaged 14 points and 5 assists per game as the Warriors point guard.

Although the Warriors lost 44 games, Gilbert excelled during his second year as point guard with the Warriors. He averaged 18.3 points per game and dished out 6.3 assists. He was named the NBA's Most Improved Player, and also gained a reputation for his strange behavior. Gilbert was said to take fully-uniformed halftime showers because he would get so frustrated with the Warriors losing ways. He was also known for throwing clipboards and chairs around the locker room. Furthermore, Gilbert claims that he only sleeps a few hours every night.

After such a successful individual year for Gilbert, it was time to test the NBA's free-agent market. Much to the disappointment of Warriors fans, Gilbert signed a 6-year, 65 million dollar deal with the Washington Wizards in 2003. Not surprisingly, he became an instant star with the Wizards. Fans loved to watch him race up the court, dish-off passes, and make difficult shots and lay ups. Although the Wizards only won 27 games his first year in Washington, Gilbert led them with 19.6 points per game. Gilbert, along with teammates Larry Hughes and Antawn Jamison, led the Wizards to the NBA playoffs during his second year. The highlight of the decade for the Wizards was their post-season victory against the Chicago Bulls in the NBA playoffs. During Gilbert's 2004-2005 year, he averaged 25.5 points per game! In 2005-2006, Gilbert again led the Wizards to the playoffs. He finished the year fourth in the NBA in scoring with 29.3 points per game. He also ranked fourth in the NBA in steals per game and was elected to his first All-Star Game.