After a total eclipse, people turn and start talking to strangers. Awe makes people friendlier.

Something large and strange happens, and the usual rule about not speaking to people in the street briefly suspends itself. Shared astonishment does that. It puts everybody in the same position at the same moment, nobody above anybody, and ordinary caution drops away for as long as the feeling lasts. Awe turns out to be social rather than private.

You do not need an eclipse to borrow the effect. Say something out loud next time you see something good in public, to whoever happens to be standing there. A sky, a street musician, a ridiculous dog.