[irrational]

How does that analogy work? Traditionally salt is very valuable. It was even used as payment/money at times (worth your salt). You can preserve food with it. It gives food flavor (if you've ever accidentally omitted salt from baked goods, like bread and cookies, you know how terrible things taste without salt).

[ryanisnan]

Have you ever been really, terribly thirsty, and just thought, "I could use some salt?"

No analogy is a perfect match, that's what makes it an analogy. The water here is the precious resource.

[what_ever]

There is plenty of salt in the world but not enough water.