I love those chance moments of connection. When I did my own grocery shopping (before I became too fragile to do it alone), I often made those connections when helping someone reach or pick up an item too difficult for them. Or, we'd be kicking our heels waiting for someone to check the stock for an item we needed and strike up a conversation.
I might never see that person again. But, more often, they're regulars at the same store. And, that momentary connection has just added a friendly face to the sea of strangers. Sure, we might only ever after nod in passing with a smile. It's still a friendly face and that makes the world a whole lot less cold.