Every contact leaves a trace
The French father of forensic science, Dr Edmond Locard, famously pioneered a principle named after himself (though I presume he didn’t choose the name himself!). In it, he says that “every contact leaves a trace”; that is, if you take an action, you’ll leave evidence of that action behind.
However, I think it applies profoundly to our interactions with one-another as well. Over the years on social media, I’ve had more fleeting interactions with total strangers than I could ever count, and I think of many of them frequently — even more than a decade later.
I think that’s a beautiful thing, really: total strangers, despite a misplaced feeling, perhaps, of familiarity leaving our mark on one-another’s lives, and likely never even realising the impact that we’ve had. We should all try to remember that day-to-day.