It is impossible to make anything foolproof because fools are so ingenious. Murphy's Corrollaries Left to themselves, things tend to go from bad to worse. Murphy's Military Laws Never share a foxhole with anyone braver than you are. No battle plan ever survives contact with the enemy. Friendly fire ain't.
Incoming fire has the right of way.
Murphy's Technology Laws Logic is a systematic method of coming to the wrong conclusion with confidence. Whenever a system becomes completely defined, some damn fool discovers something which either abolishes the system or expands it beyond recognition. Technology is dominated by those who manage what they do not understand. If builders built buildings the way programmers wrote programs, then the first woodpecker that came along would destroy civilization. To err is human, to forgive is not our policy.