Michael Schumacher says people shouldn't compare his successes in Formula 1 to those of Sebastian Vettel after the young German secured his third consecutive title in 2012.
Vettel became the youngest triple World Champion in history this year, also matching Schumacher and Juan Manuel Fangio as the only other driver to clinch three titles in a row.
Seven-time champion Schumacher, who retired from F1 at the end of the season, says what Vettel has achieved is special, but believes trying to draw comparisons between himself and his compatriot makes no sense.
Schumacher and Vettel won the Race of Champions' Nations' Cup on Saturday.
"You have to be special to do that, it's pretty simple," said Schumacher of Vettel's third consecutive title. "I don't think we need to compare. He is doing his thing in his moment and I did it before."
Vettel said he was still struggling to come to terms with the fact that he is a three-time World Champion.
"I think it's still difficult to put it in perspective," he said. "I'm not waking up in the morning and thinking of what I have achieved. I'm happy with who I am and I'm happy to wake up the next day and really go day by day, not making things too complicated or thinking about it too much.
"It's very special and something no one can take from us. I'm very proud of that."
Michael Schumacher vs. Sebastian Vettel: Comparing their first seven F1 seasons
By the numbers, the two German aces have remarkably similar performance stats over the same periods of their careers, although Vettel holds a decisive lead in pole positions.
Schumacher: 27 wins in 102 races (.264 winning percentage), 17 poles (16.7%), two World Championships.
Vettel: 26 wins in 101 races (.257 winning percentage), 36 poles (35.6%), three World Championships.