Walking is just controlled falling. Don't believe me? Take a step.
The human body has its center of mass high up off the ground, so it requires a continuously acting balance system.
When you take a single step, you shift your weight forward in such a way that if you didn't have a balancing system, you would fall flat on your face. At the last second, you swing a leg forward and catch yourself, regaining your balance. Taking a walk is just repeating the same motion over and over again.
The reason walking is not thought of very often throughout the day is because it is intuitive. It is learned and perfected early on in life, so many humans don't pay much attention to it.
Learning to walk on two legs was a major achievement for the human species, and it helped free the hands to create tools and the civilization we live in today, all because we learned to fall and catch ourselves, and then again and again.