periodic reminder that "no, I'm in the control group" is a wonderfully versatile response that works in many situations
"did you catch the Seahawks game last night?" / "no, I'm in the control group"
"do you have any plans for Christmas?" / "no, I'm in the control group"
"do you know how fast you were going back there?" / "no, I'm in the control group"
"can I get you something to drink?" / "no, I'm in the control group"