Irritating yet non-fatal consequences of the RNG?

Two games in a row: In one, the RNG put the downstair in a room that I could not find. Searched all over the map, finally gave up and quit to try again. Next game, first level of the Gnomish mines, all but a few squares are on the far side of a pit that's blocking a narrow passageway. Can't cross with my pet, haven't yet tried all the options but -- no lease, no scroll of earth yet...sigh.

What has the RNG done to you that didn't kill you, just made you stronger? (Or more annoyed, more likely?)