I leave you the best self-help quotes from great authors such as Anthony Robins, Helen Keller, Brian Tracy, Nelson Mandela, Thomas Jefferson, Ralph Waldo Emerson, Eleanor Roosevelt, Thomas Alva Edison, Buda and many more.
Simply knowing or reading is not enough, the change occurs knowing where you are going, making the decision, committing yourself and acting. From there you have to be flexible but at the same time persistent.
On the other hand, one of the ways to develop personally or achieve great goals is by observing how other people have done it. You may also be interested in these phrases of self-esteem or these of self-love.