A good engineer thinks in reverse and asks himself about the stylistic consequences of the components and systems he proposes.
The passage of time is a continuing thing. At 18, you're going to live forever, and you are definitely not at 52, so that is a recurring topic. I still think it's the main stuff.
I have been threatened occasionally. But that happens to everybody who is writing this kind of things. Threats will come without fail. It might happen to the most 'innocent' texts. If it gets too much we call the police.