The fisherman from Galilee who was planted at the center of the Empire - Simon Petrus! He was crucified upside down, with his feet uppermost.
Anyone who has observed a good sheep dog at work with the shepherd will have noticed how the dog eagerly waits for a sign from the shepherd and is positively distressed until it gets the command. Peters was like that: without the Lord, he immediately became unsure, indecisive, blundering.
The figure of Peter is an impossibility, made possible only by the will of the One who created him.