@Iken.
Well, 'how' and 'why' and 'if I'm stupid' are different Qs

Why - kinda the nature of the business, plus am a Sr Engineer/Tech Lead, and basically, when/if something needs to be done, I figure out how, and design it, fix it, or figure out how to fix it, then am still involved, one way or another, fairly often. I also wind up kinda wearing other hats as well. Plus, if you're going to do something, do it right..kinda all adds up to..bah!
How? Dunno, have pulled 72 hours without sleep before, recent 'record' in past year or so is 57 or 61, wasn't counting. It's not so bad when not dating someone seriously, as long as I get *some* free time off, like all my weekends, and don't pull it twice in the same week. Lately, both 'rules' have been compromised, so I'm kinda grumpy, ...... off, and forgetting what daylight looks like :-/
It's kinda/sorta by choice. I guess I could go into a large project group or way too large company, and 'do the absolute minimum,' but again, if you're gonna do something, do it right. Only other option would be a different career, really..but I'm good at this one. Still looking for the 'I'll work 40+ hours in 3 days, then leave me alone for 4 days' version of it..may wind up back in business for myself again at some point, dunno.
The GG. Yes, lol, I may have dreams about her tonight

Good indication it is *so* time to pull out the black book, but hey, the GGs are a very nice piece of work. Won't rule out any of the batteries, the 510/nano is just one comparison, one that should be obvious of that outcome but immediately came to mind.