Personal Knowledge Management Principle: Keep notes focused on one idea
Your personal book of knowledge or PBOK is a collection of all your ideas. The real value of your PBOK is how those ideas fit together to create your web of knowledge.
Keep each note focus on one idea allows you to use the same note for many different larger ideas.
Once you have enough notes, you will be able to assemble those notes to form larger ideas. A collection of everyday thoughts becomes a personal philosophy.