Half Empty or Half Full?

Ty and I were watching the football game Packers vs. Bears, we both wanted the Bears and they were losing. Ty said "watch they won't make the first down." I said "aren't you the pessimist?" He said "yep." I was a little surprised that he even knew what that meant so I asked him - he said it was one of his vocabulary words (so they are learning something in school.) Anyways I say "so if you see a cup only filled half way do you say it's half full or half empty." Ty's reply is classic, he said "IT DEPENDS WHAT YOU ARE DRINKING - Is it a smoothie or just milk?" How do you respond to that, so true so true.