Whenever anyone dares bring up my little shopping problem (and mine actually kinda is a slight problem, but thankfully it's not out of control), or my addiction to working out at the gym, I usually just get a little defensive back and ask, "Why do you just sit in your room and play video games and never leave the house?"
Usually shuts up the stupid coworkers pretty quickly, and for quite a while. Nerd rage = quiet time.
You really need to see a neurologist. - Wagegoth