well if you read books about magic or watch animes, they tend to go from boys who learning just to summon a flicker of fire like a match takes ALOT of concentration and effect. Many of years later after casting fire over and over and over they get use to it Now they can make a Fire ball in their hands while not even thinking about it. And yes while being attacked and having to run from other spells or sword. But then even years later he could be and old man and ccould cast an Inferno by batting his eyelash.