Hi i'm currently on my first playthrough, playing as a Breton mage currently level 13, I've been playing through the college of Winterhold and during one of the quests i realised that my magicka wasn't draining while using low level spells like frostbite and lesser ward ect. I was level 11-12 at the time of this and then suddenly it just wore off, was this a power i had temporarlily picked up or a glitch? If I did pick it up can anyone tell me how I did it?

The quest where you "repair" the light well things give you a HUGE temporary magicka regen buff. The regen is of a fixed value and so even works while you are charging a spell.

^^^^^^^^^^^^ this lol

Thanks guys, its been bugging me for ages trying to work out why it happened.