FWIW, unless one has an exceptional memory for faces (which I do not), this (frequent nodding and smiling) is an occupational hazard for those of us in my profession (as, I suspect, in several others), as meeting me professionally is a much more emotionally significant occurrence for my clients than meeting them is for me. Since I live in the same community where I work, I often run across people I have met once or a handful of times who greet me by name--and I have only the vaguest of impressions who they are ("parent of one of my students" does not narrow it down much). So I'm with you, Eagle Mum--lots of conscious friendliness and vague inquiries after the wellbeing of their families!
