When I got my second job as a programmer, I memorized the computer instructions and assembler commands in advance. I walked in on the first day ready to program. There was little else one needed to know.
Later in my career programming was more complicated. I worked with many other programmers doing similar work, and we asked each other about whatever we needed to learn.
When I became a consultant, I worked less often with groups of programmers. But programming was even more complicated. I relied on a bunch of books to learn what I needed. Each time I changed projects, I bought two or three more books.
Now programming is horribly complicated. I constantly need to find out things I never knew. But oh, the Web! It may take five or twenty searches, but beautiful explanations of everything I need are just waiting for me to find them.