Re: If I could have a dollar for every time…
Well, if we're talking cars, then I've done a massive facepalm myself.
This was back when I used to off-road for fun; I had two cars - one for that, and one for normal getting around. The 4x4 was a diesel, while the road car had a petrol engine. And as soon as I make that distinction you can probably guess: filled one up with the wrong fuel.
You'd guess right - but that's not the real facepalm.
You might also reasonably guess that I put petrol in the diesel engine. And you'd be guessing wrong with that part - I put diesel in the petrol engine.
As any driver should know, the nozzle on the diesel pump is too big to go into a petrol filler.
The real facepalm, then, is that when I was in that situation I didn't think: Problem - this nozzle is too big. Reason? It's diesel, and this is my petrol car.
Instead, I thought: Problem - this nozzle is too big. How do I get the fuel into my car?
And I proceeded to solve that problem, and filled the petrol car's tank from nearly empty to full.