There is a famous Nietzsche Quote that goes
Whoever fights monsters should see to it that in the process he does not become a monster. And if you gaze long enough into an abyss, the abyss will gaze back into you.
I was thinking about this in the context of Doctor Who. One of the coming of age rituals that the Time Lords have is to stare into the Time Vortex, through the Untempered Schism. This would be a traumatic experience for them. According to the TV show, it would drive some crazy, some would run away, and others would be inspired by it.
The Master and the Doctor are two examples of this. The Doctor ran away from it and the Master was driven insane by it. Whatever it was that they saw, set the outline for their lives. The Doctor be notorious for running away. Even during the the Time Wars, he was known for running in and solving all his problems armed only with a sonic screwdriver, but still running. He even got the Tardis to flee. The Master similarly become defined by the drumming that become a constant in his Mind. He took it as a call to war and it set his bloody goals for the rest of his lives.
The Doctor in What Keeps Their Lines Alive says, “When I was young, I looked through eternity’s eye, and eternity created me.”