Max understands sarcasm. Yesterday when we were walking back from my picking them up from X I said something like "Boy, I'd really like that more than anything!" And Max looked at me and said: "you really mean the opposite of what you said, don't you?" I was astounded! I told him that yes, I actually did, and explained that I was being sarcastic.
I don't know what I was more impressed with - the fact that he understood the whole "opposite" thing (like my way with words?) or that he had the intuition to get it.