Book of shadows doesn't need to be only spells, rituals, candle meaning, and other information.
It can be your diary. It can be where you share how your day went, who you interacted with wether they are Gods/Goddess, spirits, plants, or humans. It can be filled with what things you did on that day, and how they went. It can be where you share your emotions. It can be so much more then just a spell/ritual book.