The errors I need Google for are almost universally caused by third-party libraries. Back in the day, your software relied on significantly fewer third-party libraries, and/or you wrote the libraries yourself in-house. Languages had much smaller standard libraries. And, you always had direct access to the lowest levels of your system without OS interference, so you could work around or debug anything. So, I had no trouble without Internet just having K&R and manuals for whatever I was interfacing with.