When we realizing Dhamma facts in ordinary mind, we experience that gained wisdom disappears and re-emerges in our minds time to time. That average wisdom about the realized fact gradually deacays over time if we don't re-contemplate it regularly. So we can conclude that ordinary mind's realizations are subject to impermanence.
Should a person have to realize and know Dhamma facts until the realization/knowledge becomes non-impermanent?
Although he gained some wisdom, how this wisdom become non-impermanent?
How can he make this wisdom non-impermanent?
What should he contemplate? (after attaining Jhanas)
Should he contemplate dependent-origination and realize that all the things are dependently originated in order to realize Anicca-Dukkha-Anatta?
Or mere Anicca-Dukkha-Anatta contemplation is enough?
Should he need to realize everything (every-necessary-thing) before liberation?
Is that means he needs more time (may be lifetimes) than he thought, in order to completely know and understand everything?
What do you think about the following excerpts related to knowing everything?