Lewis Hamilton has achieved so much in his Formula 1 career already that it's difficult to foresee what greater heights he could aspire to.
Winning two more world championships with Mercedes would take him to five, which would ensure he surpassed contemporary rival Sebastian Vettel's current tally of four and make Hamilton statistically the most successful driver on the current grid by every relevant measure.
It would also neatly take him to the end of his current contract with Mercedes, which lasts until the end of 2018. Before then, he must decide what he does next.