The ancients said:

“(Self-)cultivation takes an unimaginable time (while) enlightenment in an instant is attained.”

If the training is efficient, enlightenment will be attained in one fingersnap.

In days gone by Ch’an master Hui Chueh of Lang Yeh mountain, had a disciple who called on him for instruction. The master taught her to examine into the sentence: “Take no notice.”
She followed his instruction strictly without backsliding.

One day her house caught fire, but she said: “Take no notice.”
Another day, her son fell into the water and when a bystander called her, she said: “Take no notice.”
She observed exactly her master’s instruction by laying down all casual thoughts.

One day, as her husband lit the fire to make fritters of twisted dough, she threw into the pan full of boiling (vegetable) oil a batter which made a noise.
Upon hearing the noise, she was instantly enlightened. Then she threw the pan of oil on the ground, clapped her hands and laughed.
Thinking she was insane, her husband scolded her and said: “Why do you do this? Are you mad?”
She replied: “Take no notice.”

Then she went to the master Hui Chueh and asked him to verify her achievement.
The master confirmed that she had obtained the holy fruit.

There are two paths to the ultimate truth. The first is of self-cultivation and the second is of enlightenment. The first is basically wrong. It only appears to be a path; it is not. One goes on and on in circles, but one never arrives. The second does not appear to be a path because there is no space for a path when something happens instantly, when something happens immediately. When something happens without taking any time, how can there be a path?

This paradox has to be understood as deeply as possible: the first appears to be the path but is not; the second appears not to be a path but is. The first appears to be a path because there is infinite time; it is a time phenomenon But anything happening in time cannot lead you beyond time; anything happening in time only strengthens time.