P.S. One more thing

A postscript written vertically on the left margin of a letter page from 1714 (source here).

The P.S. — that postscript that still sneaks into our letters, emails, and even texts — has surprisingly endured. Despite the tools in today’s digital age that make organizing and editing simple, we still love to tack on a “P.S.” at the end of a message. Why?

The …