The rocker reveals that the late leader was his mentor and hero and the leading figure behind his decision to become an activist for world change as a teenager, reported Entertainment Weekly.
In the 1051-word piece, titled 'The Man Who Could Not Cry', was published on Time magazine's website hours after the news of Mandela's death was released.
"As an activist I have pretty much been doing what Nelson Mandela tells me since I was a teenager," Bono wrote.
The singer, who has become a leading light in the fight against Aids and world poverty and an international rights advocate, called Mandela a "forceful presence" in his life, adding his idol was a "hardheaded realist" and a "compromiser without being compromised".