Don't you hate it when...

you're standing in line at Starbuck's and you see someone you recognize so your brain triggers your mouth to break into your customary "Oh, hi! Good to see you!" smile and your arm muscles start to contract into a slight wave as your eyes search out the mutual contact and THEN you realize - "Oh, shit! I actually don't like that person! I don't want to talk to them. Abort, abort!" - so you quickly drop the smile and the arm and you have to completely switch focus and concentrate instead on hiding behind the person waiting in front of you???

Yeah, I hate it too.