Survival equipment

A company is organizing survival courses. The invited specialist asks the employees as an introduction: “What do you think are the three things that are most necessary when you are lost?” “A compass, water and a deck of cards!” one of the secretary answers quickly. “But what do you need the cards for?” the specialist asks in amazement. “But how then?! Just start playing solitaire when someone inevitably says behind your back: “Stupid! You should have put down the black ten, not the red one!!!”