Massage works very deeply and usually also slowly. The muscles of the body are innervated by nerves that listen to them and also talk to them. Massage works to get that system of muscles and nerves communicating more clearly- and more peacefully. If we take this analogy a bit further, it could be said that pain in the body is loud. Massage clears up some discord and creates some space and opens up a dialogue in the body between some parts that have not been working well together.
Many clients come for massage and they think one massage will make all their pain disappear. I liken this to imagining that I want to lose twenty pounds and get in shape to run a 5K. I hire a personal trainer and work out for an hour. When I leave, I get on the scale and have not lost any weight. When I try to run, I am still winded. I tell my personal trainer he misled me. I have not lost twenty pounds and I still cannot easily run my 5K. He told me if I worked out, I would get in shape. I storm off and believe his workout did nothing.
This seems silly when we look at it through the lens of exercise. Massage is the same way, though. Regular workouts and regular massage make the body pump its fluids around- which keeps everything clean and healthy. I try to get a massage once a month. Sometimes it is once every two months. In times of stress, it might be once every two weeks. Whatever the pace, though, the regularity creates the change- just like with exercise.