The Japanese saying ichigo ichie translates as "one time, one meeting". The expression is frequently associated with the Japanese tea ceremony (chadō 茶道), where the intereaction between the tea, the host, and the guest is unprecedented and unrepeatable. Each meeting, each sip, is unique.
The saying also works well for students of Zen who come to appreciate that all encounters are unprecedented and unrepeatable. All new, all perfect - if you really pay attention. There is no "same old, same old".
[NOTE: The lovely tea cup, as well as the Bāozhŏng oolong tea in it, were gifts from a student (see Go Drink Tea). The tea table is a cross-section from a very large, old tea tree (Camillea sinensis L. Kuntze) from Yunnan, China].