Sometimes, I think it's helpful to see myself as my brother's keeper when out and about in the world at large.
Like the other day at Costco.
I was cruising through the store, kid-free, knowing exactly what I needed and exactly where it was. As I powered up the bread aisle, I overheard a pleasant-looking 70-something gentleman asking another shopper."...gluten free bread? I've been up and down this aisle for 30 minutes now, but she told me I wasn't allowed to come home without it." Though he was smiling, there was a slightly-panicky note in his voice, like, "I don't really like shopping at Costco on a Friday morning with half the state of Wyoming, but I might never get out of here!"
Since gf bread was on my list, I leaned over to interject myself into the conversation of which I was not an invited member (this is where my "brother's keeper" mentality overrides my "mind your own business" mode). "It's on the end cap, up there on the left."
This man, if you could have seen the look on his face, you'd still be giggling, too. It was like he'd been given a real-life "get out of jail free" card. Sometimes people don't like it much when we inject ourselves into their lives. But, sometimes, I get to be a "brother's keeper" and it makes both of our days.