100,000 people met in 50 years, that’s meeting 5 new people every day including week ends. That seems hardly believable. The article probably meant 100,000 encounters. Which is still massive.
He lived in a time were personal meetings were still very normal. And he was in a trade were meeting many people was normal and beneficial. I would say anyone in that business meets that amount of people and even more. But he was one of the rare people who also documentated it well, while being relevant enough, to make an article about it.
Meeting people doesn't neccessarly mean he know them all personaly, or had more then a handful encounters with them. Like if you have a big company-meeting with dozen on dozen relevant people, it's quite normal to go around and exchange contact-information, talk a bit, and never meet again or use the contact-info.
I would imagine that at least a portion of his life must have involved sitting in his office and meeting a long line of people waiting outside sequentially, each coming in to ask him for a favor, pitch an investment, or similar -- the image in my head being something like the opening scene of the Godfather.
I'd imagine doing that one could have substantive somewhat personal meetings with 25-50 people or more on an average working day. Not to mention larger gatherings, speaking to groups, a day spent in the halls of a legislature, or similar.
