Someone recently asked me that thinking back on my whole career, what am I the most proud of. I thought for a little and said "being able to retire early". I sort of said this tongue in cheek, but upon later reflection, this is the truth. Sure, I had my moments, and have some certificates, awards, pins, etc. But that all pales in comparison to being able to RE (although a lot of that may be in hindsight - as time goes on, everything I did at work becomes less and less significant in my life). If someone had asked me that when I was still working, I probably would not have answered "Continuing down the path to retiring early at some point". What about others?
Absolutely. I'm also pretty proud of the book that many of this site's posters helped me write.
On the military career side:
The submarine force has a publication that lists lessons learned from the operations that "we do not discuss". Due to our nuclear-trained culture, it's mostly a recitation of the flawed logic and poor decisions which led to dire outcomes when we should've remained undetected. It also comments on bad teamwork and emotional responses to tactical situations. Over the last 40+ years that this collection of reports has been carried in classified safes, it's generally considered a Very Bad Thing to have your story in there. Your consolation is that you survived the events which got you written up in the first place.
When you even utter the title of this pub, submariners (particularly officers and sonar technicians) grimace and mutter an expletive. The analyses are written about the watchstander so the people are anonymous, but whenever you're training on one of the incidents from this pub (hopefully to avoid repeating it during your upcoming deployment), some grizzled steely-eyed killer of the deep always says "Yeah, that was Wild Bill Schmuckatelli on USETAFISH. We had a few brews at the club one night and he also said..." Again, while the lessons and the learning are critical, you don't want to be the guy who got into the pub in the first place.
Anyway one of my submarines was once, um, "conducting submerged operations and training in international waters", when we poked our noses into a tactically interesting situation. I was the Officer of the Deck and I unexpectedly turned it into one of those critical tactical situations that include the phrase "of great importance to national security" on the award citation. This time we managed to do everything right in a very urgent (but ultra quiet) hurry and we remained undetected while collecting a large database of... sensor data. We managed to help the intel analysts correlate a whole crapload of stuff that we really wished we hadn't been in a position to learn in the first place.
When we filed our mission report, someone at the analysis center thought it was important enough for the whole series of events to be written up in the pub. (Not my idea!) It included a lot of commentary about what can happen when you get aggressive about poking your nose into tactically interesting situations. Surprisingly, this time it said "The OOD executed all of the correct actions, and the watch team remained undetected while..." At the time it was the only chapter of the whole pub that admitted someone had somehow done something correctly.
And for a couple of years afterward, during our training seminars my fellow submariners would ask me "Hey Nords, that was you, right?"
That was a good feeling.