The Comedian had also been a Vault dweller.
Of a Vault that he had decided to deal with problems in a more philosophical and spiritual way.It's good to summarize the concept with the phrase
"in this Vault there was a corridor and two rooms."
The inhabitants did not know how long this corridor was, but they knew that in the other room there were deathclaws, yes because deathclaws existed long before the bombs. Man is an evolutionary species and therefore when stressed or in difficulty he will make updates, because he is not the smartest, meanest or most intelligent; but who adapts. 
They were all people who already had exceptional basic skills,
for example The Comedian had perceived and seen things much earlier and this had led him months earlier to take a plane just to be there.
The whole time he was in that room he did nothing.
He was waiting for that light to turn from red to green.Now the important thing is not how the Comedian left the room, but how the other "survivor" also left.Of course there were also other rooms in the Vault, the inhabitants ate, slept and the light in the room was red.
There was a man who decided to do nothing but look at the light, trying to turn it off with his gaze perhaps?
Let's speed things up a little, the light turns green and then that's it.
But then the deathclaws arrive and then the other one also comes out of the room and at that point the concept is clear.
What was the point of leaving the room if that world needed someone...