Learning standards
Jeffrey Zeldman in 2001:
“We can watch our skills grow obsolete, or start learning standards-based techniques now.”
That advice is still largely valid, even while a lot has changed in the way people build websites and web-based applications. Tools change, standards get updated, but the practice of focusing the learning on the more stable core building blocks carries people forward.
More about the early years of the web can be read from Year of A List Apart, a blog post from 2017, written by Jay.