I have noticed that the more literate a culture is, the ability of its members to remember is decreased. I have noted this in myself. With this current information age that we live in, it is far easier to remember the source of information rather than the information itself. Better yet, have a tool that maintains information sources for later reference.
This was the motivation for my first work "Expert Shell Scripting". I had collected a large number of shell scripting techniques that were very useful and I wanted to create a useful resource for my bookshelf that contained all of them in one place.
I collected these through many hours of work and research throughout the last decade in my role as a UNIX/Linux system administrator with Intel.