Ichi-go ichi-e (一期一会 means one time, one meeting) indicates something that happens in your life once and never happens again. It refers to the idea of treasuring the unrepeatable nature of a moment.

A comparable phrase could be You cannot step into the same river twice (Heraclitus).

I came across this word via Priya Parker’s The Art of Gathering 📕 where she uses this idea (inspired by the Japanese tea ceremony) to view gatherings as purposeful, intentional once-in-a-lifetime opportunities to meet with other humans.