Two elderly people.
Cycling back from work I encountered a stranded elderly woman with a flat tire on her mobility scooter. Now, here in Sweden people have a tendency to be awkward in interactions with strangers in a bind, but I'm... Weird (I'll get to that later), so I stopped to check what I could do. She had a spare scooter in her apartment, but that meant I alone would have to enter her home and get it. I didn't mind, but she made a point to mention that she'd have to trust me on this. I'm guessing because I was 21 at the time, and looked (and still look) a bit like a meth-head.
Got her scooter just fine, and got her (and the broken one) back to her apartment. We got to talking, and steadily her daily life started to dawn on me, and for the first time I had a real glimpse at a person who was truly at the end of their life. Friends and family gone; a body that had long since begun to fail her; her days spent alone, save for the odd social worker that came and helped out every now and then. And it became clear to me that she was simply happy to have someone, anyone, to talk to. And the sad truth being that someday, If I'm lucky, I'll be in her place.
The other one had been an elderly man, a couple years back. I was sitting at the bank, the queue machine had broken down, so people had been forced to be orderly the old fashioned way. He came to sit next to me, polite the way swedish people are. Now, I have a dissociative disorder, which means that emotionally, strangers aren't very different to me from friends or family. I can ignore common courtesy, in fact, I mostly do - I can't really help it, since I don't really feel shame or shyness (or much of anything else, really). He notices immediately that I'm engaged to interact. I have nearly nothing in common with a person of his generation, save that we both draw breath, but it doesn't matter; he's a well of life with an abundance of jokes and anecdotes. He probably could have entertained me for hours...
It's a sad thing, what life will once rob of us. When almost everything we've ever known will have returned to the cold earth - replaced with new tomorrows, so full of people we'll never know.