Professor M. Gazi Yaşargil: an appreciation by a former apprentice.

An appreciation of Professor M. Gazi Yaşargil is presented as part of the celebration of his selection as Neurosurgery's Man of the Century. The early history of microneurosurgery and the immense contribution of Yaşargil to the development of this methodology are reviewed. The impact of Professor Yaşargil on the development of specific operations and instruments is an important aspect of his role in creating this change in neurosurgery. Without trying to predict what history will remember, it is safe to say that every neurosurgical procedure performed today has been affected by Yaşargil's efforts. In the broadest way possible, he has dramatically changed for the better how neurosurgery is "thought, taught, and performed."