COLD or Sinus Infections

KNOCK ON WOOD  for me, but I haven't had a cold, sinus infection or bronchitis since my surgery in 8/2006. How about anyone else? I usually get a sinus infection and sometimes bronchitis in the fall, but nope nope-not me, not last year, or this past fall. Coincidence? (I am a non smoker to begin with, in case some were wondering if the no bronchitis was because I stopped due to surgery). Who else?? HMMM???