I write this in the hope that my son, Telbaril, someday understands why I did what I did.
Learning proper magic is something they teach you here at the guild, but it is not the only way. There is so much knowledge that is traditionally forbidden by the decrees of those who fear true power and those who wield it.
Know that there are places beyond Tamriel where the cunning and the wary can go to learn forgotten spells. I speak of the planes of Oblivion. The sea of limitless dimensions contains an endless series of islands. Some are controlled by the mighty Daedric Princes; others are loosely connected to one minor Daedra Lord or another. On these islands, creatures dwell who possess secrets out of time. Some are there of their own volition, but others are banished there for crimes either heinous or imagined.
If you are reading this, Telbaril, know that I found one such place long ago. Know that it is not far from the city in which you now sit within a tiny cave by the docks. It is called the Crow's Wood.
And son, if you decide to follow me, bring all of your cunning with you.