Some 30 years ago, when I was in high school, I was working as an electronic tech for a small electronics manufacturer. I was troubleshooting a board and didn't know what a chip's function was within a circuit. I took the schematic of the board and went to the owner of the company, the person who designed the board, and asked him what's this chip doing? He looked at the schematic for a few seconds and said let's go to the Library. The Library was the companies' library, this was before the days of the Internet, it was a good sized room with shelves from floor to ceiling stocked with manufacturers data books. After some time he found the book on the chip in question. After spending more time reading about the chip, he took the schematic and explained to me what the chip was doing and how the entire circuit worked.
All this took well over an hour. I felt a little guilty spending that much time on a board that didn't even cost $20, not to mention the time the owner of the company had spent on it. I told him I was sorry for the amount of time he spent on this and that I thought since he designed the board that he would have just remembered what the chip did. And I've never forgotten the words he said to me - "Pat, the intelligent man isn't the one who memorizes everything. The intelligent man is the one who can figure everything out."