[@Achronum] my understanding is that they might have dabbled, but think of harry potter, there is so much to learn that no one really has a head start. Plus there will be some mages that come from purely human back grounds. I mean, my guess is a earth user could push a rock or something, the same way someone might learn to play a song by watching someones fingers, but they cannot just play another song, they come to school to learn the notes ^^I also suspect that some with more abstract magics dont really even know WHAT it is that they are doing. 

#teacher

Edit: disclaimer: not the gm, just an educated guess