The 32-year-old Serbian striker, who now plays his football in Belarus for BATE Borisov, admits he has no regrets and would not change anything in his football career.
Kezman, who is now playing for his 12th club, was at Chelsea during the 2004-05 season after signing from PSV Eindhoven but bagged just four goals in 25 appearances for the club before moving to Atletico Madrid.
But the player says he will never forget his time, admitting to Sportske: "Chelsea was the best thing in my career. That was the climax of my career, for sure.
"Living and playing in London was something that I will never forget.
"I don't know if I made a mistake because I moved away so quickly. Maybe I do and maybe I don't regret it, but I always believe in my decisions.
"But the transfer to Chelsea made my dreams come true. That was the best thing that ever happened to me.
"Maybe I could achieve more and I could have been more successful at Stamford Bridge, but I don't regret anything."