Lewis Hamilton is already targeting his fifth Formula One title and will not "do the easy thing" by following former team-mate Nico Rosberg into early retirement.
Rosberg interrupted Hamilton's reign over the sport by claiming the drivers' world championship in 2016, only to sensationally walk away from the sport just days later at the age of 31.
Hamilton took advantage of the German's departure to reclaim the crown at the Mexican Grand Prix on Sunday, the Briton making it three titles with Mercedes and four overall.
"Four is a great number. But I want number five now," the former McLaren driver told a news conference.
"I want to go out at the top… I could do the easy thing, like obviously Nico did, which is just stop and retreat with these four titles. But I think there's more in me.
"I think there's more to come, more of a challenge. There's harder times ahead and I like that, I love that. That's challenging and it would be so boring without it."
Level with Alain Prost and Ferrari's Sebastian Vettel on four titles, Hamilton trails only five-time world champion Juan Manuel Fangio and seven-time winner Michael Schumacher.
Should Mercedes' recent dominance over Ferrari and Red Bull continue, the 32-year-old can harbour realistic ambitions of setting a new record for F1 championship triumphs.