"Doing something is expressing our own nature. We do not exist for the sake of something else. We exist for the sake of ourselves. This is the fundamental teaching expressed in the forms we observe. Just as for sitting, when we stand in the zendo we have some rules. But the purpose of these rules is not to make everyone the same, but to allow each to express his own self most freely."
--Shunryu Suzuki, Zen Mind, Beginner's Mind
As "rugged, individualistic Americans," we naturally resist the formality of Zen practice. We've grown up thinking that we're supposed to be unique, so it's not easy to start following a bunch of Zen "forms" that dictate a standard way to walk, sit, and bow. If you've gotten interested in Zen through reading and meditating on your own, you might have your own style that works pretty well, and so the extra formality practiced in a Zen center might seem off-putting.
Newcomers to the San Francisco Zen Center sometimes stand in the middle of the meditation hall, looking horrified or bewildered, when everyone starts bowing to the floor at the end of evening meditation. I had the same experience the first several times. The thoughts running through my head went something like, This is crazy. Don't drink the Kool-Aid. You're smarter than that.
In spite of the great practical benefits I had experienced from other Zen practices, I refused to believe that the forms, especially bowing, served any purpose. Nevertheless, I stuck with the schedule to see what might come of it, and I'm glad I did.
I eventually came to appreciate the forms, including bowing, for what they are not: they are not my idea. Someone else created them and passed them down, and then other people followed them and passed them down. Now everyone learns them from someone else. It almost doesn't matter what the exact forms are. It just matters that you pick them up from someone else. This takes the ego out of its normal executive position, allowing you to experience a different, more free-spirited, way of doing things.
At first, the ego puts up a real fight. Your inner monologue fills with every excuse in the world to not follow the forms. But eventually, you see that it's okay. You manage to survive the forms. You even manage to survive the bowing. On top of that, you can enjoy yourself. You can enjoy the calmness and the clarity of the experience when you don't have to plan every little move. That's how your ego slowly learns that it's okay to let go.
You also see that you continue to be yourself, even when you're doing exactly what everyone else is doing. All of the weird behaviors that we cultivate to assert the uniqueness of our identity prove to be unnecessary--it really doesn't matter how we dress, or what music we like, or what other people think of us. At best, those superficial characteristics are just expressions of the personality that is already there. No effort is required to be yourself. This is not easy to see unless you intentionally stop trying to be unique. Then you see that you're going to be unique no matter what, and you can redirect a considerable amount of time and effort toward things that are more meaningful.