What do I think you ask? For myself, I feel that powerful magicians are analogous to athletes like "DarkestKnight described. Some are born naturally gifted while there are others with a lot of motivation and practice, can achieve similar results. However, I also find that what Lady Eva alluded to having a difficult childhood can also shape one’s perception and abilities. My experiences tell me all this to be true. All the tarot card readers, spirit readers, and astrologers have told me that by birth I’m gifted with abilities but need to work on developing them.
Interestingly enough, a Wiccan witch told me that due to my severe childhood abuse, as a coping mechanism, I learned at an early age to escape my abusive environment by moving my consciousness outside of my body. Essentially, while my body was physically abused, I was numb to the pain because my consciousness was elsewhere. As a consequence of moving my consciousness outside of my physical body, I have a greater awareness of spirits and energies around me.