The odd sight of smooth, round river stones piled one on top of another would have drawn attention. People would wonder, providing an opportunity to recount the story of when their powerful God parted the waters and led the Israelites into the Promised Land. Many generations would remember that God generously provided.
God knows us well. He knows we forget quickly and need physical reminders of His work in our lives – maybe a photo or trinket instead of a stone monument. Remember often. Then use the memories as a weapon to combat worry. When your mind begins to fret, remember your powerful God has worked things out in the past and trust that He can and will generously provide again.