Ronaldo said: "I have been totally surprised by how many goals I have scored as I am not even a centre forward. But to be the best in the world I have to win titles like the Champions League and the Premier League.
"It is not easy to win anything, especially not the Champions League. I think if you win that then you go down in history and that is what I want."
Ronaldo, 23, who yesterday showed off his Barclays awards for player of the season, Golden Boot and 30-goals, has already played a demanding 48 games this season for his club and will be starring for Portugal in the summer's European Championships.
But he said: "No player gets tired when they are winning games and trophies. This is the type of situation now that players dream of. Manchester United is a 'superclub' and we are obliged to win things every season. So tiredness does not come in to it.
"Next season we will be obliged to repeat what we have done and I'm sure that we will."