You cannot run a business, or anything else, on a theory.
Harold S. Geneen
Geneen has it right which is why he was a titan in the business world. He headed up ATT when it grew to its zenith. Theory doesn't win the fight against pragmatic business experience. That's why it is good to experiment and learn new business skills from doing them.
Inactivity is the big business killer. Couple it with apathy and you are dead in the water.
Every failure is a learning opportunity, every success is an earning moment.
If you don't learn you won't earn.
Be bold and muck in.