I always feel that if I answer "yes" to "can I help you?" it implies that was just randomly bumbling around the shop like a lost idiot, too incompetent even to ask for help.
This happens to me constantly. I aimlessly wander around the store muttering to myself, "Doesn't anyone work here???" Especially prevalent in big-box situations. Ordinarily, I am delighted when I am approached by an actual human being.
