“I now remembered what my alcoholic friends had told me, how they prophesied that if I had an alcoholic mind, the time and place would come—I would drink again.” (Page 41, Big Book)
Imagine being in a room at the top of the tower. Below the room is a chasm extending to the bottom of the tower. Now imagine there is a room above the room, which can be accessed with a rope ladder and trap door.
Now imagine you’re told the floor of the room you’re in could give way at any moment.
Your only hope is to get onto the step ladder.
You do so, because, even if the floor has not given way yet, it could give way at any moment.
Note you do not need to go all the way up the step ladder to be safe: you need merely be on the step ladder.
This is the precise position of someone alcoholic who is newly sober. The floor could give way—one could drink at any time, and, if one drinks, that might well be curtains; one might well not survive the drop. One does not need to clamber all the way up the step ladder to be safe: one need only have stepped off the floor onto the step ladder.