In Australia you learn about base-N numbers in primary school, I don't understand why you see that as a huge undertaking. Ultimately if you ever have to check the mode of a file on *nix, or interact with bitmasks in any way, you're going to run into numbers in different bases. Not to mention memory addresses when debugging.

I mean, it's not _mandatory_ but it's something you'll run into eventually (though since I do quite low level systems programming, I expect that I see hex a lot more often than web developers -- though CSS colours are also in hex).