Here's a weird one. I was on an American airlines flight, sitting in coach on the aisle.

Drink service comes by. I order a Coke.

She gives me a can of coke and also uses the little plastic cup to scoop a cupful of ice our of the basin and hands me the cup of ice.

The problem is the the cup is totally overfilled with ice so that the ice is well over the rim of the cup. I knew that if I poured the coke over the ice, I would only be able to get a tiny bit of coke into the ice filled cup, and then I would have had a difficult time drinking the coke without getting a face full of ice every time I brought the cup to my lips.

So as she was getting someone else's drink, I reached over to dump half of my ice back into her little ice basin.

She politely stopped me, took my cup, walked all the way to the back of the plane, presumably dumped out half of it, and then brought back the cup with a more reasonable amount of ice.

I guess I understand this -- once a passenger is served food or drink, no part of that food or drink goes back into service. Probably a good health rule. It was a bit weird though because the cup of ice was only on my tray for about five seconds, more or less within her view the entire time.

I actually like ice. Usually a lot of ice. Some of these flight attendants are crazy though with scooping out a totally full cup of ice and expecting people to drink around the ice.