From my view, (by the way, I am not a so called believer of any so called religion, and I don't believe any school of thoughts who thinks they know so much that others should follow their teachings. Therefore, if you're not comfortable with reading something different from what they've taught you, don't read.) Zen may be from Buddhism (Actually in my opinion, Zhuang Zhou is a more important source of zen.), but far beyond Buddhism. And the founder of zen is not Bodhidharma or Siddhārtha Gautama，but Dajian Huineng， no matter what kind of legend or fairy tale they're telling you. Or, we can put it like this: Because of Dajian Huineng and his Platform Sutra, Chinese zen is totally different from the Indian zen.
From the platform sutra, we can see that at that time ( in tang dynasty) there is a popular Buddhism practice of stopping thinking in meditation. It is still popular now, because someone can get all kinds of experience from it (Maybe due to Law of the lever or Principle of leverage, to suppress thoughts can't empty your mind but full it with so called spiritual experiences) even some sort of superpower or super knowledge. They might think what they've gained are proof of their awakening. But I don't think so, from my view, anyone who mistake a new dream as so called reality and think they've found the ultimate truth as if "the matrix" has not really awaken from dreams at all. (They don't ask that if a matrix is behind the scene of everything, then what is behind the matrix. And they take their dreams so seriously that they're so nervously busy.)
Since he hasn't realized he doesn't need any proof. All kinds of proof are just dreams or shows of vast varieties. No matter how so called spiritual or special or even unique, they are mere shows instead of the platform, the stage.
And according to Dajian Huineng, we'd better not to mistake an empty nothingness as Móhē Bōrě or the Móhē (Maha), the biggest, the hugest, the greatest. The biggest one is not based on the small ones.( None of the small ones can be the source, the images on the screen can't control the TV set.), including a small temporary emptiness.
No matter how usually it is for us to build a castle with small Lego pieces.
The biggest one ( the big platform) is the background and the source of all kinds of small ones（all sorts of shows or dreams).
Thus, the right way is not to block the streams in your mind, including trains of thoughts，but to let them flow as their wishes. You are not the streams or trains, you are the rail or the great huge river-way or the sea, the ocean. The Tao 道, in Chinese also means the road or the way.
Therefore, you are the Móhē (Maha), the biggest, the hugest, the greatest. When you've really awaken, you have true faith in yourself, and you don't need any proof anymore. ( Anyone who need a proof don't really have the faith.) And there won't be any proof, no one can see the whole self, since anything before you for you to see is merely a part of it, small and temporary. So we have to use metaphors instead of point at it directly. (Refer to my other answers, e.g. Min John Zhou's answer to What are the five aggregates of Buddhism? )