LeBron James celebrated his 40th birthday on Monday with gratitude for his basketball longevity and optimism about his future with the Los Angeles Lakers. "To be honest, if I really wanted to, I could probably play this game at a high level for about another – weird that I might say this – but about another five or seven years, if I wanted to," James said. James already has one of the longest careers in NBA history, but he knows it's nearing an end.