I remember - in the 1990's - reading that we would all have individual, portable telephones one day. It was hard to imagine back then... Now it's hard to imagine being without one!
For those of us who've been around for the development of cell phone technology, the changes have been mind-boggling! Like computers, a phone a few years old is quickly outdated!
(Compare that with land lines - some of the phones in our house are 20 years old!)
One of my sons (who's in his 30's) asked if we had an old phone around that he could trade in. His cell phone plan was offering a $150 discount on a new phone with an older phone trade-in. But his current phone was still good and he wanted to keep it as a back-up.
I'll check, but it might be too old, he told me when he saw it...