Painful memories of the past tend to be very human, as it were. We often focus on ourselves and others as we recall difficulty, and may forget the involvement of someone else who was there as the most important party in every experience.
"God... worketh all things after the counsel of His own will" (Ephesians 1:3; 11).
Nothing has ever happened in the life of born again believers in the Lord Jesus Christ that was not either determined or allowed by our Heavenly Father. Thus, we must never traverse the path of remembrance without Him. When we visit the past, we must always go there with God, and to God.
Certainly He was there in our blessings, and was in fact the Giver of them. "Every good gift and every perfect gift is from above, and cometh down from the Father of lights." We all have a deficit of thanksgiving, and fond recollection of good things and good times forms a holy altar of gratitude when memory is graced with expressed appreciation for Divine gifts of grace. "When I remember Thee upon my bed, and meditate on Thee in the night watches. Because Thou hast been my help, therefore in the shadow of Thy wings will I rejoice" (James 1:17; Psalm 63:6-7).
Our Father was also there in our challenges, directly orchestrating some for purposes of maturing, disciplining, chastening, and perhaps most importantly, preparing us for ministry to others. Other pains resulted from the sins and injustices of a fallen world, and should not be viewed as the direct design of our Father's hand. However, just as no devilish or fleshly thing has ever happened in God's universe that He did not allow, so is this true in our personal lives. Nor has anything happened that took Him by surprise, or that He will not "work together for good" in the blessed purpose of conforming us to the image of the Lord Jesus (Romans 8:28-29). Certainly His allowances may be mysterious in the details, but there is no mystery in the overarching "shadow of Thy wings" under which every moment of our lives has been lived.
Again, when we visit the past, we must never go there without God, and we must go there to God. He was the great reality, the great fact, and the great influence of all, and we will one day see that nothing in our lives will have been wasted. Our Lord is that wise, that powerful, that loving, and journeys to the past with Him and to Him illuminates both blessed and difficult memories with the glorious light of the God who was there, even as He is here.
"I will remember the works of the Lord; surely I will remember Thy wonders of old."