Just a funny anecdote:

Today, on GUA-LAX in C class (lunch flight), the Purser was refilling wine glasses. Both my wine and water glass were half empty. As she leaned over me and asked if I'd like more wine, I said: "Yes please. And also more water, whenever you get a chance."

Her response was: "Yes, I see that your water glass is empty. I've been trained properly. Since I see your water glass empty, I'll refill it."

What does she do next? Pours white wine into my half full red wine.

Her response: "Well........I haven't been trained to do THAT!"

Great flight, by the way. ^