I'm with ya, I'm also extremely lucky that I was able to start this off small scale, part time, almost more of hobby, so my gear pile was able to grow extremely fast. So I learned the basics, then jumped right to the new shiny stuff.
Old school is so fundamental and so important because it is ALWAYS there. It doesn't really matter what you forgot, lost, or broke, knowing how to go back to old school and get sh@t done can make the difference between getting the job done or having to come back another day and lose money. I did a few practice climbs using a single rope with a blake's hitch when I first got into tree work just because I saw it and it looked super useful and I had not come across any system like that in rock climbing. Then I got into the unicender and rope runner, but that base is still in my noggin for when its needed.
About a year and a half ago, I watched a friend experimenting with positioning on a wall for photography and we did 3 other climbs while he floundered around with different pieces of gear and configurations and got himself exhausted, then a few months later I learned about DRT using only 1 rope and 1 carabiner - Blew My Mind!