Want to feel old? Are you old enough to remember flash bulbs and (more recently) flash cubes? Good... this is necessary. Now... find someone who is under 20 and try to explain a flash cube to them.
They will look at you like you are crazy, I guarantee it.
Just went through this at the Smithsonian Air & Space Museum. A movie was playing in one of the exhibits where the narrator mentions something looking like a flash bulb. Wife and I commented that no young person would understand that line... so a few minutes later I decided to put it to the test. See results above.