The great fights with your strongest rivals are always the biggest motivation. When you win easily it's not the same taste.
Motivation is the key. More than training, more than experience or age, motivation counts. You have to ask yourself: 'Why am I racing?' I race because I like it, because I'm really enjoying it. I like to set up my bike and ride it on track. After 20 years in the GPs I'm still highly motivated. Everything else is a consequence.
I never race for records. The motivation to try to beat the record is not enough to continue. You have to enjoy it.
Fortunately during my career I have won more or less everything, so I need to enjoy it to have the right motivation.