Moses was reminding the Israelites of the importance of remembering their past: how God had made promises to Abraham, how God redeemed them from slavery from the Egyptians, and how God brought them into the Promised Land. And in truth, God didn't just bring them into the Promised Land, He provided for them every step of the way: they had food to eat, water to drinks, and clothes and shoes that didn't wear out – for 40 years!
But Moses understood something that we're quick to forget – just like the Israelites. When it comes down to it, we face the temptation to think that we are where we are because of our own strength. We're the ones who worked hard; we're the ones with ingenuity; we're the ones who studied and practiced and made it to the top. But such thinking is so far from the truth! God is the one who enables us to work; He is the one who gives us creativity and ingenuity; He gives us our talents. We cannot forget this! We cannot forget that God is the One who deserves the credit for where we are in life. By whose strength? By God's.