Erving Goffman described a small ritual that happens constantly between strangers in public spaces as civil inattention. Where you briefly acknowledge another person with a glance, perhaps a moment of eye contact, and then look away. The message is subtle: I recognise your presence, and I also recognise your right to go about your business without being disturbed.

The glance matters, and so does the release. Hold the gaze for too long and the meaning can change. What initially communicated acknowledgement can begin to feel intrusive, confrontational or like an invitation to engage. You have crossed an unwritten social boundary. It is a remarkably simple interaction: glance, acknowledge, release. I think much of social life depends on rules we rarely discuss, yet most of us learn to understand them intuitively.