Signs of age: when even adults are too young to share your past

A few weeks ago I heard a bang outside and thought 'car back-firing', then I wondered if that still happens, and if it doesn't then what do young people attribute unexplained sudden noises in the street to? The more I thought about it, the more I realised how many familiar everyday things from my childhood (though I grant that some of them were already old-fashioned) are completely unknown not only to children but many adults today and would require explanation in a story. Among them are:

1. the long, frustrating search for a working payphone

1. hoarding coins of a particular denomination (10p for the phone, 50p for the electricity meter)

1. crossed wires on the phone

1. older relatives answering the phone using the old 3 or 4 digit version of their phone number

1. people answering the phone by reciting their phone number

1. yellow headlamps on cars that had been to Europe

1. foolscap paper

1. cheap cameras with no focus control, and separate flash cubes

1. having to limit yourself to taking 24 photos on an entire holiday

1. Betamax vs VHS

1. floppy disk drives (particularly five and a quarter inch)

1. only having 4 TV channels to choose from (and they shut down overnight)

1. piling as many kids as possible in the back of an estate car for a day out, sometimes with a couple of dogs too

1. wondering what to do with the (entirely detachable) ring-pull from a can of pop, maybe getting a moment's entertainment by wearing it as a ring

1. hoping to hear a song on the radio, or searching charity shops, car boot sales and second-hand record shops for years to find it, instead of being able to reach for spotify or YouTube

This undoubtedly happens to everyone as technology and fashions change, but it does give you a realisation of the passing years. Anybody got any more examples to share from their perspective?