No-one can escape difficult days. It's just part of life. Things might not go to plan, or you might miss the targets you set yourself - but the moments themselves aren't what count. What really matters is how you react to them, because you learn the most in tough times and grow stronger as a result.
Valtteri and Lewis have their own ways of retaining the fighting spirit that powers them to success.
Valtteri's state of mind is shaped by the Finnish concept of 'Sisu'.
"It's a mental power," he says. "A will to succeed and never giving up. Never, ever giving up. I think that's it in a nutshell.
"This strength of not giving up on your goal, even if you need to go through a stone wall. You might have setbacks at the beginning of a race - but you've just got to keep on going.