For me, It's the incredible (at times overwhelming,) amount of information and how easy it is to access. There's always been people doing amazing things, but it was for the most part one on one exchange of ideas or read as much as possible. This is a fascinating subject to me .. I've had many conversations with two friends, one 26 yrs younger and the other 10 yrs older than me about changes. A good analogy about how these conversations go, is compare a car today to one 30 years ago...talk about opening a can of worms.
A few things off the top of my head that I had no experience with: Having live plants delivered, LED lights, gravel vacuum, live bacteria in a bottle, root tabs/liquid fertilizer and the term 'nano tank' was new to me. I'm sure there's more, i just haven't learned about them yet! Ha