The Traveling Wizard is a man of minor repute. He has made great impacts on a few places and people. Those that know him, know him to be powerful. However, most do not know him, for he travels the world. He seeks experience and knowledge, craves adventure. The journeys of the Traveling Wizard seem to never end.
When you sleep, your soul briefly returns to the place where it was created/goes to when it dies, and seeks nourishment. Everybody's soul is created with a little link (or you could say a greater entity calls it back) to that place so that it can return easily, but upon death, the soul returns via that and annihilates the link as if returns.
Also, as an added thingy, you could say the entity supplying the link, or residue of the links themselves, (whichever) is the source of all arcane power.