If we were to divide zazen into two parts, practice and experience, we could consider each part separately. We could say that we practice in order to achieve enlightenment. But your perceptions cannot be the standard of enlightenment, because deluded human sentiment cannot reach the standard of enlightenment. Basically, you cannot know your own enlightenment because whatever you call enlightenment can't be enlightenment.
~Master Dogen, as translated (paraphrased) by Brad Warner