During my first introduction to Zen I was not aware of zazen or the way it is presented today: Zen is about sitting for long periods of time on a cushion. The Zen I was introduced to was in a college classroom by a professor who knew D.T. Suzuki very well (even had ice-cream with him). I saw no films about Zen (this was back in 1964) in which monks were doing zazen. My Zen came from D.T. Suzuki who was Rinzai. In the books of his I read, zazen was not of importance the way it is in Soto Zen these days. Zazen was a useful means, but not the only means.
Looking back on this, my Zen journey began with, let's say, the theoretical, and ended up in practice or what in Chinese Zen is called gongfu in which the adept throws their entire being into trying to achieve awakening. This is probably the right way to go rather than starting out with practicing zazen which can become somewhat meaningless without understanding what it is aiming at.
We have to remember that Zen's goal is not about our ability to sit for long periods of time in a rigid posture that zazen demands. Zen's goal is seeing our true nature. This nature is not something for sensory consciousness, either. It is most primordial. It is the very stuff from which our thoughts are composed including physical reality.
Zen's uniqueness is not zazen or koans. It is about telling us what the real goal of Buddhism is; making its goal simple and straightforward. It is too easy to get wrapped up on the sitting side of Zen as if that will lead us to kensho. But sitting with a group of people is not all that conducive to seeing what this nature is. There has to be some theoretical groundwork done before we undertake the practice of zazen (the Four Slogans of Zen never mention zazen). This way we can insure that Zen as dhyana is practiced not just in the form of sitting but during the time when we work, because dhyana or Zen is not a physical thing. It is about penetrating through the layers of our thoughts from gross to subtle until we find the substance of these thoughts—our true nature.