What is the origin of the idiom "once in a lifetime" and when to use it?

The idiom "once in a lifetime" is believed to have emerged in the English language as a figurative expression to describe a unique or extraordinary event that is unlikely to happen again in a person's lifetime. It is often used when describing travel experiences to extraordinary destinations, witnessing natural phenomena like eclipses or meteor showers, participating in significant cultural or sporting events, or encountering rare opportunities in one's personal or professional life.