It happened after a particularly bad stretch for Tails, when one of his allies had been turned into a homicidal robot that beat another one of his friends into a coma, and the kingdom taken over by an evil wizard. It makes sense, then, that when Tails himself was confronted with that kind of loss, he'd seek out his father to find out how Amadeus dealt with the psychological toll of watching your companions suffer as the result of a seemingly endless conflict.
