"I will not be negligent to put you always in remembrance of these things, though ye know them, and be established in the present truth" (II Peter 1:12).
We can "know" God's truth. We can even be "established" in it. But we will still need to be reminded of it throughout our earthly lifetimes.
The Apostle Peter knew his calling to awaken believers to the realities of who our Lord is, and who we are in relationship to Him. He knew that the best and brightest among us are nevertheless needful of remembering the reality of the Lord Jesus Christ in the many blessed aspects of His person and office. Life in a fallen world can distract and deceive us, and at times we all seem to aimlessly wander down paths of unbelief that we have encountered before, to our own detriment. We should know better, and there is no excuse. However, our Lord does not refer to His trusting children as sheep for no reason. These animals are not considered to be the smartest of God's creatures, and thus require the shepherd's constant attention in protecting them from peril. So do we, and thankfully, our Great Shepherd is merciful and patient with us in our times of forgetting "those things which are most surely believed among us" (Luke 1:1).
Realizing this about ourselves will go far in leading us to do something about it. We will more consistently expose ourselves to the light of God's Word that helps to keep our path brightly illuminated. We will pray, and ask God to keep His truth fresh and increasingly enhanced in our minds. We will fellowship with other sheep who recognize their own need to be put in remembrance of our Shepherd's presence and provision. Perhaps most importantly, we will realize how utterly dependent we are on His constant devotion to our benefit. "I have gone astray like a lost sheep; seek Thy servant" (Psalm 119:176).
"Lord, I forgot." We will have to confess this at times in our earthly lives, and bitter tears may accompany our admission. Again, forgetting is not an excuse because our Heavenly Father has "given unto us all things that pertaineth to life and godliness" (II Peter 1:3). However, we will find Him patient, understanding, and forgiving even as He does not condone our waywardness. Our Great Shepherd is a "great shepherd," and He is also a "good shepherd" (Hebrews 13:20; John 10:14). He does not forget us, and He knows His sheep. Even more, He loves His sheep, including me and you who are far too prone to forgetfulness of His perfect faithfulness. He is willing to remind us, and to send Apostle Peters our way who "will not be negligent to put you always in remembrance of these things."
"He hath made His wonderful works to be remembered: the LORD is gracious and full of compassion."