Never had cause to reverse a string but have needed to reverse an array. Never had cause to do something like fizzbuzz but have needed modular operator (actually both in the same function) but if I had never had reason to validate barcodes of differing lengths and validate the check-bit, I would probably fail on fizzbuzz too. In fact I probably would fail today if asked, who has time to remember something that useless, and that easy to look up?