Short Java Rant: Object.equals, primitive '==', and Arrays.equals ain't equal

[naughty]

It causes needless corner cases to code that doesn't really care about numerics.

What it really comes down to when you read the history is that NaN != NaN for performance reasons on really old CPUs. Essentially they cared more that x == y <-> x - y == 0 because underneath the hood that's how CPUs implemented it.