Back in my late 20’s I did memorize the book of James, along with many other long passages that were meaningful to me, including the entire Sermon on the Mount, several Psalms, 1 Peter, and I don’t remember all the others now. I would not be able to recite them all today as I could then, but the words are still in my heart, ready for God to use when he wants to. It has been worth the effort it took. I just learned one new verse a day and each day would say the passage as far as I had gotten. I still try to memorize verses that have special meaning for me. Memorizing is good for keeping our brains sharp as we get older.
I first memorized the passage from Ephesians 6 you quoted when I was in Vacation Bible School. It must have been in the fourth grade. I still remember making a sword of the Spirit, a breastplate of righteousness, a shield of faith, and a helmet of salvation. Funny how those visual aids helped impress the verses on our young memories.