You notice small things when you're walking. There is a lizard who likes to sun itself in a certain spot on the sidewalk. It's almost like meeting a friend each time I see it. Even more interesting is a tiny burrowing owl just off a trail that likes to sit at the head of its burrow and watch the world go by. It blends in so well you would never see it any way but walking.
If you are observant walking the same route frequently doesn't get boring; quite the opposite. If a certain plant catches your eye you can watch it bud out in the spring, see the flowers form and then the seed pods. You wouldn't notice that if you walked a different route each time you went out.