Same age as I am, 66.
Some personal reflections:
I worked for Clancy, though I didn't really know him. We "met" back when I was on AOL, probably in the early 90's, during a discussion about snubnosed revolvers. There was a line in one of his books to the effect that such weapons were useless past a few feet. Since he was something of a gun-nut, with a shooting range in his basement, I was surprised to hear this. I pointed out that even a so-so handgunner such as myself could keep them all on the silhouette at fifty yards all day with a .38 Special snubbie, but he didn't believe it.
I was sorry I never got a chance to go to his range and show him. I was but a small fish in his well-stocked pond.
Of course, my time in the trenches on the Net Force novels starting in the late 1990's was considerably more important than the pros and cons of short-barreled revolvers. There were ten of these books, which I wrote, (and later co-wrote, with Larry Segriff,) near-future stories in which I got to pretend I was a techno-thriller author. I had fun with them, especially the first few, working under the aegis of Marty Greenberg and Steve Pieczenik. I never tried to write like Clancy, but put my own spin on things, such that it was.
There was also a YA series, but I had nothing to do with that one.
Early on, I came up with a device that, for all intents and purposes, was the iPhone; I got to introduce the art of pentjak silat to a large audience; and play with virtual reality in holodeck-like computer scenarios. Got classical guitar into a couple, all kinds of boomware, some gun fun facts, and how to beat somebody up real good using a cane.
I dabbled in politics, military stuff, and secret federal agencies. It sure beat working for a living.
One of the novels came out of a Google search in which I plugged in the search term "Death ray." That got me to HAARP, extremely-low-frequency stuff. In the novel, I had the evil scientist driving people crazy using the ELF. That guy who went bananas at the Navy yard recently thought that was what was happening to him, but I don't think he got it from me–it's a common delusion among a certain strain of schizophrenics, that somebody is zapping their minds with various kinds of waves.
There was a Net Force TV miniseries, starring Scott Bakula, which I'm sure he'd like to forget, since it was maybe the worst such ever aired. Bad. Really bad ...
Working for Mr. Clancy paid a lot of bills around here, and allowed me to tuck some away for retirement, plus it put my name on the New York Times Bestseller list ten times, (including a couple when I wasn't getting cover credit.)