One of the most unhelpful and destructive ideas of the last few decades has been "what I own"
Apart from encouraging us to think about things rather than people (which misses the point of being human, frankly), it also serves to devalue the things we own in common. They clearly can't be worth anything if everybody owns them, can they?
Things like the great 110 year old St Pancras Baths which re-opened today after a 3.5 years refurb
Splash....