If you're walking that awkward distance behind someone - where you're too close to be ignored, but still pretty far away - and the person in front of you holds the door for you:  Speed it up a notch, shorty! Unlike many people - I will lose patience with your sense of entitlement, and I will let go of that door right at the moment where you have to quickly catch it to avoid being hit with it.  And even though all you can see is my back, you can be sure that I'm grinning.