We either trust in the Lord will all our heart, or we lean to our own understanding. The natural tendency is to lean on one's own wisdom. We trust in what we have learned through our experiences in life, both good and bad. We trust in what we have learned from the culture we have lived in. We trust in what our denomination or group that we have identified with. We trust in our feelings about things, but have a hard time really and truly trusting in the Lord with all our heart in everything. If the Bible says "thou shalt not..." and we do it anyway, we are NOT trusting in the Lord. If the Bible says "thou shalt..." and we refuse to do it, we are not trusting in the Lord, we are leaning to our own understanding. Next time you have a dilemma in your life, or a problem, or anything that perplexes you, stop and take a good, long, honest look at yourself and see how much you are leaning on your own understanding to figure it out, and how much you are really trusting in the Lord about it.