The advent of the wheely bag totally revolutionised luggage. No more back-breaking, awkward hauling and dragging of large rectangular suitcases. Those little wheels changed everything. Telescopic handle - click, click, click - lean forward and away you go silently on those glassy-smooth airport floors.
That big, heavy bag is no longer the ungainly beast that it once was. It's even acceptable for a fair-sized piece of carry-on to be wheel-enabled getting you right to the aircraft door leaving you only having to pick it up for the final few steps to your seat and the overhead bin.
But what about luggage that's smaller than that? Are wheels acceptable on a briefcase, for example? I've seen things that look like wallets-on-wheels being confidently escorted by men in suits apparently unaware of the shame they're bringing to their kind. Just pick the thing up, for crying out loud.