The first knock on a stranger’s door is the hardest. By the twentieth, it’s just knocking.

Almost all of the difficulty is loaded into the first repetition, because that is where the imagining happens. By the twentieth the act has lost its meaning and become a motion, and the fear you had at the start turns out to have been about the idea rather than the thing. Nothing about the doors changed.

Get the first one over with quickly rather than preparing for it further. Then do several more in the same session, since spacing them out lets the dread rebuild. Volume is what flattens it.