Reminds me of that one time I was sitting on a tram going to school and an older guy came to me and shown me a card. I thought it was ticket control, so I showed him my tram pass and he nodded and went away. Only then did my sleepy brain manage to realise what was on his card - that he’s disabled and wants my seat. Apparently he mistook my card for something similar too, since he didn’t argue and just went away.

I did jump up and let him sit afterwards, but it took me a bit to realise what just happened.