The rich vein of form Lewis Hamilton continued after securing the 2018 title with two races to spare shows he has become a different driver, according to Mercedes boss Toto Wolff.
Hamilton wrapped up his fifth world championship at the Mexican Grand Prix, which he followed up by claiming pole and victory at the remaining two races in Brazil and Abu Dhabi. On the previous two occasions he had won the title before the final race, in 2015 and 2017, he failed to record a win in the remaining events.
On top of his own success, Hamilton was part of a Mercedes team that secured a fifth consecutive constructors' championship, which it did at the Brazilian Grand Prix.
Wolff thinks Hamilton's commitment to helping continue the team's spell of dominance explains this change in mindset.
"He has actually driven stronger after winning the drivers' title," Wolff said. "I feel he is so embedded in the team, and integrated, that the drivers' title felt incomplete. For a driver it is really strange, because they are calibrated on a drivers' title, but he said it felt incomplete and we needed to seal the team title.
"When you look at his face, there was almost more relief and happiness about sealing the constructors' title than the first one. And that is why he just didn't take the foot off the throttle until the very end.
"That is somehow a new Lewis."
Hamilton and Mercedes are edging towards some of F1's biggest records. Hamilton is now two world championships from Michael Schumacher's seven and is closing in on the German's tally of all-time victories -- he has 73 to Schumacher's 91.
Five of Schumacher's titles came in Ferrari's dominant spell at the beginning of the current century. The Italian team claimed six straight constructors' championships between 1999 and 2004 -- Mercedes can match that achievement if it successfully defends its title next year.