Eventually only one is left.
Mostly true. Sometimes both partners go out at the same time though. If my wife were to die before me, then I would basically become alone. But I do not mind being along. If I did I would seek out some companionship with someone who is also alone.
He said (I have to paraphrase):
"I've heard all this crap about you better get married or you're going to die alone. Let me tell you, death is not a team sport. People rarely get to go out together. And if you are an old guy who lives long enough and ends up in a home, there are so many women coming at you that you feel like a machine gunner at the Chosin Reservoir in Korea fighting them off!"
I wish I could remember his exact words, because I found them funnier than what I could piece together, but...I get what he means.