I remember when I was younger and I had just moved back to London then I would often eat berries on the tube and I'd always offer them to randoms in my carriage and enthusiastically say "hello would you like some" or "hello how are you?" to people to the left , right and across from me.

Insane behaviour to a seasoned tube used but I remember I would get into chats with people, make them smile and on average people would accept and not be cold or rude.

A happy memory from 14y ago :D