Definition & Meaning of "blast from the past"

What is the origin of the idiom "blast from the past" and when to use it?

The idiom "blast from the past" originated in the United States in the 1960s, likely popularized by radio DJs playing records and songs long forgotten. The term refers to something or someone reminding you of an earlier time, often surprising you because you have almost forgotten about them. It is used to talk fondly about something that has returned after an absence or a period of disuse or obscurity.