My dad was born in 1931. He was too old to understand smartphones before he died, but he did have an iPod Nano and he told me one day that it astounded him that he had gone from 78 rpm records as a child that would shatter if you dropped them and could only have one song on each side to a tiny plastic and metal square that held thousands of songs. He remembered, as a classical music lover, when the LP record was introduced and it was amazing that he could listen to full pieces of classical music without interruption whenever he wanted.
He amassed a massive record collection and then a massive CD collection. The audio devices got smaller and smaller, the media got more robust, and then one day he didn't even need to collect all those CDs. He could just rip all the ones he had, put them on his iPod whenever he wanted, and then just get more from the library from then on.
And it just blew his mind that he was actually able to do that and listen to all of it on this little square.