Historic presidency and charisma have made him a rock star on international scene

US President Barack Obama bid farewell to the world stage on Sunday, pondering his legacy, offering advice to his successor and discussing his post-presidential life at the end of his final foreign tour.

His historic presidency and charisma have made Obama a rock star on the international scene, even at times when the daily grind of politics dimmed the glow around his election as the United States' first black president in 2008.