A few years back, I had my old 45 RPM records out to look through and my daughter asked what they were. I explained that back in the 1960s before CDs were invented, this was how we listened to music. I further explained how all the bands issued singles on these "45s," and radio stations would rate the top 40 songs every week.
She was quite impressed as I continued describing how one used a phonograph to play them.
I burst out laughing when she asked -- perfectly straight faced -- "Daddy, how many megs of RAM does one of these hold?"