On and off over the last 15 years or so.
Only recently have I become much more comfortable & able to resolve things without resorting to search, stackoverflow etc.
The turnover point was the day I finally learned vi & cron so I could fiddle with an old Buffalo NAS, that was long out of support, riddled with security holes, and offered only very limited tooling.
Was a great learning experience, but it didn’t pan out the way I wanted. So it runs Debian now, supports modern protocols, and continues to serve. Amazing what you can keep in service when you try.
evs.ee at least offers ISO standards at a not extortionate price:
https://evs.ee/
The pdfs do have some DRM on them and they will come watermarked with the buyer details though. The former is easy to get around - I used foxit reader and a pdf ‘printer’ to make a copy that opens nicely in anything.