One of my favorite Scripture-memory-related moments near the beginning of memorizing Romans came when I wasn't memorizing or practicing.
I had already memorized part of Romans 1 at least through verse 9, and maybe through his entrance into the Gospel topic. Verse 9 includes, “For God is my witness, whom I serve with my spirit in the gospel of His Son.”
I remember one day going about my business, thinking about things happening in my life, and at one point thinking the phrase, “with God as my witness,” and found myself immediately and naturally adding onto that, “whom I serve with my spirit in the gospel of His Son.” It was so cool and encouraging.
Hiding God's Word in one's heart can be a reminder of whom we serve and why we are here!