One day the iPod was everywhere and the next it was nowhere. But this device that propelled Apple toward the iPhone may never be forgotten.

It surprised the world that Apple, of all companies, was the one to produce a hit music player when so many others had failed. But then it absolutely shocked the world when Apple itself killed it off.

In retrospect, the iPod was a light bulb product. Suddenly it was switched on and it was everywhere, but then just as suddenly it was switched off and gone forever.

Or nearly forever. It's now a quarter of a century since it was first announced on October 23, 2001 and from when it first appeared in stores on November 10 that year. All these years on, the iPod is gone yet seemingly never forgotten.

You may be among the (literally) millions of people who remember it fondly.…