At the risk of getting slapped about by the women on here, it is just a fact of life that the majority of the folks in this category whom you will run into in your life are females. Most of them are elderly ladies, and perhaps it's because they outlived their husbands and have no one to talk to. It just builds up, and then you come along. Some have offered the theory that the reason women outlive men is because the men got talked to death, or just died to escape the daily blather. And, when women do this to a man, it is harder to be impolite and roll your eyes to the ceiling or look at your watch, or just say, "Would you mind taking a freaking breath, here?"
The thing I've always wondered about this is how the person rattling on incessantly can not know that you lost interest somewhere along the way. I mean, do they just not get body language? Are visual clues things that have no meaning to them?
But the worst I've ever encountered was a guy who used to work for me. He was perhaps 5 years younger than me, but neither of us were just out of high school, if you know what I mean. He had just come under my supervision, and I was trying to be a good boss. So when I needed directions one day to an area of town he was familiar with and I was not, I asked him how to get there.
That was at exactly 9:30 one morning. At 10:30, he had gone from telling me the directions to this place, into a story about a relative of his who used to live near there, to the mother of that relative who had moved to Tampa, FL, to the neighbor of that mother of that relative who had been in a bad automobile accident, and it was just going on and on and on. It made that ride at Walt Disney World look like a 30-second commercial. I was looking at my watch, shuffling my feet, throwing my head back and moaning, and he just kept on and on. I do believe (and that was several years ago) that I'd still be there listening to him if I had not just finally jumped up and said, "Enough! I have heard enough!"
I later found out that no one in the organization would talk to him. I became part of that group.