This same thing happened to me, except I was in the USAF and I performed conventional munitions (non-nuclear weapons) maintenance.

As part of this work, detailed manuals were provided with maintenance routines, service intervals and all kinds of top secret detailed information, and they were maintained (by me) with updates regularly. These were absolutely fascinating reading, and on a slow week I found myself reading several of the "Theory of Operation" sections for various weapons.

A great deal of thought goes into killing people. Far more than your imagination would lead you to believe. Now you're imagining a lot more. It's WAY more than that.

I couldn't really stomach the work after that and I started getting heavily depressed.