I am seriously considering making magic users in my AD&D 1E game specialize, so to speak, in a specific type of magic use.
There are those who use alchemy/potions for the most part, those who use incantations/spells, those who use siglas or runes and even those who use gemstones for the basis of their magic.
Not to say that a magic user couldn't use the other types of magic.
In my own imagination, to try to learn all those types of magic as an apprentice would be overwhelming. I can see focusing on one type and dabbling in one or two of the others.
Perhaps one could come out of apprenticeship with one focus of study and gain ability to do others as they increase their experience and strength.