Knowledge is a precious thing. Much like muscle, it fades with disuse, but it also grows if you work at it. But not just any knowledge. It has to be something useful or fun. Grandma would always ask what I was learning in school and she was genuinely excited for me to tell her all about it. She always made sure that I had books to read. Her interest helped to instill a life long love of learning. You should always feed your knowledge.