You can read every great self-help book, listen to lot’s of intelligent people, you can have all the knowledge of a lifetime at your fingertips. But it is worthless, unless you apply that knowledge to the now and the future.
All this learning is of little benefit otherwise, other than to remind you the next time you make the same mistake, that you had already done that before and not learnt.
Apply the knowledge, that you’ve had to spend a great deal of time learning, often in some cases quite painfully.
The main thing that holds us back is fear of applying it, as that often requires changing ourselves.
So be bold, make the changes and apply the knowledge.