A lot of these search problems are easier to wrap ones head around with the keys analogy: finding a moon around Saturn, or finding a lost ship on the ocean* is

A lot of these search problems are easier to wrap ones head around with the keys analogy: finding a moon around Saturn, or finding a lost ship on the ocean* is like losing your car keys in a field then trying to find them with a pair of binoculars. If you do actually know where they are then you can easily see them with the binoculars but if you need to perform a search it is laborious because of the relative scales. * https://en.m.wikipedia.org/wiki/MV_Arctic_Sea https://en.m.wikipedia.org/wiki/MV_Arctic_Sea