About 4 years ago, I was a grad student in astrophysics at Princeton. Dyson worked at the Institute for Advanced Study which, while not officially part of the university was essentially an extension of the various departments (shared colloquiums, any researcher there was a valid thesis adviser, etc.).

The grad students have a tradition (or used to) called “Thunch” (Thursday Lunch) where they invite someone to come have lunch and hang out every week. It was by far one of the highlights of my life — maybe 10 people in the room max, eating pizza, shooting shit with some of the most impressive and accomplished people you could hope to meet — Nobel prize laureates, Neil deGrasse Tyson, famous authors, whoever would respond to our invitation (people tended to say yes). Dyson was one of them. At the time he was already like 92 years old, dressed in a suit, occasionally using a handkerchief, and this guy had just published a result in Nature. The guy was SHARP at 92. Nicest, most interesting person I have ever met. Knew Einstein from his early days at IAS. Worked on an early version of the space program that looked into launching people into space with large spring loaded contraptions that were to be propelled with nuclear weapons. Those were the days I guess...

So sorry to see he’s gone, the guy was a living legend.