What's "back in the days" mean?
Native speaker’s answer
Rebecca
"Back in the days" is an expression used to refer to a time in the past, usually a period in history. In the case of this video, it is describing a time before people commonly slept on mattresses. It's most often used with a descriptor following it that explains the time period. Ex: Back in the days of no electricity, people used candles for light. Ex: Back in the days of feudalism, people often had short lifespans. A similar expression, "back in the day" (without the plural "days") is used to refer to a time in the past, but is more often used in situations in which one is recalling or looking back on the past fondly (usually used when talking about one's childhood or youth). Ex: Back in the day, we used to ride around the city on bikes. Ex: Back in the day, I used to go to the pool with my family in the summer.
