Ikkyu’s attainment is very dangerous. You can’t just mouth these words and act like you’re already there. It sure as hell better come from some real attainment.
The danger, in Zen, is that the radical, true seeing — when expressed by serious practitioners like Ikkyu — can be understood so simply and directly in words, that then the one who reads the words doesn’t feel they need to do the actual true work at arriving at that insight for themself. “Oh, I get it!” It would be as if you were shown a photo taken from the summit of Mount Everest (or from le Marais in Paris, if you’ve never been there, or the Lower East Side of Manhattan) and you develop the mistaken belief that you know what it is to view things from Mount Everest or le Marais or Tompkins Square Park. Because you don’t know that view from someone else’s photo of that view, and you can’t. You need to have the experience of arriving there through your own efforts, and seeing the view of that photo with your own eyes, if you truly wish to live as one who sees the world from Everest, and can help others to actual summit that.
Ikkyu speaks these words with the lived experience of one who has fully attained what he describes. And he has had his view confirmed by a keen-eyed Teacher. Just smoking a joint and thinking that not giving a shit anymore, and allowing any action to be called “the Way” or “attainment” or “Zen”, is being mistaken in the extreme. This damages not only the one who thinks this way, but it can seriously harm others. If unchecked, such a mistaken view leads to a kind of nihilism. In a sense, you need to start from the “opposite” of Ikkyu’s view and, making great effort in practice, with sangha, you might one day reach the great spiritual climax of his words.