"Well, it's usually hard to tell. Most ponies get their cutie mark the first time they realize what their talent is, and especially if it's a magic talent and not something like being good at chess, there's no good way to tell the difference between not being able to do it beforehand and just not having done it yet. Maybe if I was an ordinary pony I wouldn't have found out I could make my horn not glow until I was eight, but here I am doing lots of magic before then."