A dream’s impossible architecture rarely has to defend itself until you wake up.

Impossible things pass unchallenged while you are inside them. The staircase that leads back into the room you left raises no objection at the time, because the part of you that checks for consistency is not on duty. Scrutiny is not a constant; it is a function that can be switched off.

Which raises a question about waking hours. Certain settings, tiredness, strong emotion, being in a group that agrees with itself, lower the same checks. If you notice you have stopped questioning something, ask whether that is because it is sound or because the conditions for questioning are absent.