Set this position up on a real board: white king e5, white pawn e4, black king e7. Nothing else. With Black to move, Black loses. With White to move, it is a draw. Same three men on the same three squares, and the only difference is whose turn it is. If passing were allowed, this position would be dead level and half the endgame books ever written could be thrown away.
Play it through. Black is not allowed to sit on e7 and block the pawn’s path, so 1…Kd7 (or 1…Kf7, and White goes the other way with 2.Kd6). After 2.Kf6 the white king has slipped round the side, and the rest is arithmetic: 2…Ke8 3.e5 Kf8 4.e6 Ke8 5.e7 Kd7 6.Kf7.
Black never made a mistake. Black simply had to move.
Why the rules give you no way out
The Laws of Chess say the players move alternately, and there is no clause anywhere allowing a player to decline. Your only two escapes are the ones that end the game. If you are in check with no legal reply, that is checkmate and you have lost. If you are not in check and still have no legal reply, that is stalemate under Art. 5.2.1 and the game is drawn on the spot, which is why stalemate rescues so many lost positions. Notice how strange the reward structure is: having some bad moves loses games, having no moves at all can save them.
Zugzwang, and how to put someone in it
The word is German, zugzwang, compulsion to move, and English never found a shorter way of saying it. This is not a rare curiosity for composers. It decides most king and pawn endings, plenty of rook endings, and it is the engine behind king and rook against king, where the defending king keeps having to step back because there is nothing else it is allowed to do.
Getting the other player into zugzwang usually means handing the move back to them, and the tool for that is a king walk that wastes a turn while keeping everything else the same. Three squares, one waiting move, and the burden is theirs: that is triangulation. The position at the top is decided by the same idea under a different name, the opposition, which is just the arrangement where the kings face each other with one square between them and whoever has to move gives ground.
When you catch yourself wishing you could pass, stop and count. A position you would happily keep forever is a position your opponent is trying to hand back to you, and the zugzwang puzzles are all built on that one wish.