Real Madrid's Brazil legend Ronaldo signed for AC Milan Tuesday in a 7.5 million euro deal keeping him at the San Siro till June 2008.
"It's breaking my heart but that's life," Ronaldo told reporters.
He thanked "all the fans" and "all the coaches I've had, bar one" - a clear reference to top Italian coach Fabio Capello who recently took him off the first-team list.
Ronaldo, 30, was pronounced fit by Milan doctors Friday.
Milan coach Carlo Ancelotti said Monday he soon expected to be handling 'the Phenomenon' - with a little help from an old friend. And he stressed that Ronaldo was sleeker than some have suggested.
"He's not fat, just heavy-set. Now we have to get him match-fit and hungry again".
Ancelotti said he would ask for tips on how to motivate the player from Gigi Simoni, the coach who got the best out of Ronaldo at Inter Milan, helping Inter to the 1997 UEFA Cup - still its most recent international success.
"(Simoni) had a great rapport with Ronaldo and he can tell me how to fire up the player".
Ancelotti said he could slot in alongside Italy pair Alberto Gilardino and Pippo Inzaghi or play "on his own".
Some Milan players think a fully fit Ronaldo could return to his former pomp.
"Ronnie is an all-time great who can still achieve a lot," said Brazil team-mate Kaka' of his teenage idol, while Milan icon Paolo Maldini said Ronaldo was "the greatest opponent I've faced, after Maradona".
The veteran Brazilian's fitness has been a key factor in the negotiations.
Ronaldo, who was cruelly nicknamed 'El Gordo' (Fat Man) during his first struggling days at Real, is still reportedly some way off his fighting weight.
The player put on four kg at Inter, contributing to career-threatening right-knee injuries in 1999 and 2000.
But he still scored 49 goals in 68 appearances for the club, and emphatically returned to form at the 2002 World Cup, scoring two goals against Germany in the final and claiming the tournament's top scorer prize with eight goals.
He is the World Cup tournament's all-time top goalscorer with 15 strikes from 19 games.
Ronaldo has two World Cup-winning medals and has scored 62 goals in his 97 Brazil games.
His strike rate has always been, as his nickname suggests, phenomenal: 42 goals in 46 games for PSV Eindhoven, where he broke through as an 18-year-old sensation, 34 strikes in 37 appearances at Barcelona, and 83 goals in 127 matches for Real.
He has been voted FIFA World Player of the Year three times, a distinction he shares with former Real team-mate Zinedine Zidane: in 1996 (youngest winner), 1997 and 2002.
He is a two-time winner of soccer's more prestigious prize, the Ballon d'Or as European Footballer of the Year in 1997 and 2002.
One of Ronaldo's main aims at Milan will be to win his first Champions League trophy. This year he is Cup-tied but he plans to help Milan, currently 9th in Serie A, claim a Serie A Champions berth.
Ronaldo's European honours are the 1997 Cup Winners' Cup at Barcelona and the 2002 European Supercup for Real.
Some think the Phenomenon could re-appear at Milan.
Kaka', who admitted to "dreaming" of playing with the superstar when he was a schoolboy in Brazil, predicted:
"A recharged Ronaldo will be a major asset to Milan because he's still able to decide a match in the twinkling of an eye".
