What's this?
I does not know
Not that
Not now
These four lines can be used as a mantra to facilitate being lucid in the dream of life by making a blue bunny out of the question What's this?.
When the reply affirms I does not know, the observer is consciously detaching from automatically running the belief system, and may inquire further rather than be subject to the automatic problem-solving consciousness of the implicit memory.
The assertion Not that is recognition that what is perceived is nevertheless manufactured by the mind as it must be embellished with story (concept) in order for it to seem real (believable) in the dream of life.
Rather than attach to these objects built upon past experiences, erroneous conclusions and preventive strategies, the observer may move on to the fourth line which addresses the illusion of time with Not now, simultaneously reducing the concept in Nevermind fashion.
This four-liner broadly covers the same territory as the three strings of five , but takes a more direct punch at the concept of "I" which, while it is included in the first string of words, often overlooks itself. (That's easy to do when it lacks any real substance and is programmed for self-preservation.)
There is not anything conceivable that can take away one's freedom. But the unchecked identification with the I as self, and belief in its information content, which is all recalulated from past experience, can produce a deluded sense of freedom which cannot be attained or which when thought to be attained thus becomes just another limiting condition.
Of the four lines, the re-minder, I does not know, can be powerfully influential in letting go of that which does not serve being fully lucid to the true unconditional nature of self. Be Lucid!