We “forget” God’s teaching when we revert back to old habits and ways in times of stress and temptation. Don’t!
Proverbs 3:1-2 My son, do not forget my teaching, but keep my commands in your heart,  [the promise:] for they will prolong your life many years [in regard to God’s plan for your life] and bring you prosperity [not always monetary: spiritual, relational, in health, happiness, fulfillment, etc].
James said it this way:
James 1:22-25 Do not merely listen to the word, and so deceive yourselves. Do what it says.  Anyone who listens to the word but does not do what it says is like a man who looks at his face in a mirror  and, after looking at himself, goes away and immediately forgets what he looks like.  But the man who looks intently into the perfect law that gives freedom, and continues to do this, not forgetting what he has heard, but doing it—he will be blessed in what he does.
Practice, practice, practice. We practice holiness. We are given righteousness and are kept blameless. We don’t have to worry about falling; Jesus is our safety net, our harness (like a gymnast on a trampoline), and our Teacher/Coach who helps us learn from our mistakes and to practice correctly. In piano, practicing something wrong only ingrains wrong playing. The same is true in batting, running hurdles, and nearly everything. God’s Word and His Spirit will show us how to live righteous and holy lives–just like Him–if we will give ourselves to Him today. Then tomorrow. Then the next day. Etc.