A couple decades ago when I was an undergrad and a research assistant, the director of the lab I worked in knew Vint Cerf from the ARPAnet days. I ended up visiting his house in McClean, VA and helping him with tech support. It was basic stuff like setting up wireless access point, printers, and other things. It wasn't that he didn't know how to do it, but he was busy working on other things.
I remember he was very nice and liked to talk about the underlying protocols with a bit of glee in describing them. I didn't know then that I would go on to get a phd many years later and gain a much more in depth understanding of his work, and a lot of the work that came later built on it.
He also asked me to help a disabled friend with some computer issues in her DC condo once.
He paid very well for that help, and for my broken car window from when my car was broken into helping the friend in DC (grrr).