My (I was 8) first computer (not PC) I got beginning of the 80s when there were only BBSs with, at least in my country, not much programming info (pirated software, images, stories, text games, porn). I had a Basic, assembly and C book second hand and I bought the occasional magazine and listed/disassambled existing software I typed over from mags or downloaded. That was all that was needed: the rest you had to make up by reading in the manual or experimentation.

For my current hobby projects I use things like C, Forth, Lua: languages and libraries I can keep in my brain and do not need internet for to write things that work. Compared to commercial work it is especially the fast changing things (often changing for no apparent reason) like JS projects and/or some web/app frameworks that really require Google. Certainly the best practice to use a library for everything, even when unstable or rapidly changing, is a pain. It is often much faster to write things yourself without having to debug yet another library but you keep thinking you are wasting time and fall for it. With internet not available you have to find a solution yourself. Using a lib is usually the better solution but just writing things without Google just feels better to me.