The soul grows by subtraction, not addition. — Henry David Thoreau
Matter grows by addition.
The more matter you add, the more you have.
Sure, sometimes you must remove some matter to make space for a new one, like nature does. But, in the long game, you keep adding.
It's the same thing for knowledge.
The more knowledge you add, the more you know.
Sometimes, you must unlearn something to learn something new.
However, the soul grows by subtraction.
Don't worry; it does not mean you must give away the matter you hardly gathered or the knowledge you acquired.
You can become very knowledgeable or pile a fortune while nurturing your soul.
The subtraction that grows the soul is an inner one. It's about subtracting all the beliefs, conditionings and attachments that stop your soul from shining. Sometimes, you may need to subtract material stuff or unlearn something you know to allow you to do the inner subtraction. Just don't let things you have and know to stop you from doing your subtraction work.