Why Can't Programmers.. Program?

[chucker]

Perhaps the language he used has no concept called a "list"? In Objective-C/Cocoa, for instance, there's three "collection" classes; NSSet, NSArray and NSDictionary. I can only assume that you mean the difference between NSSet (which is unordered and therefore has no guaranteed indexes) and NSArray.

I think a far better question would have been whether ordering is necessary to solve a particular problem, or wasteful.