First of all I wish to make it clear that for me ‘first Satori’ means experiencing the beyond for first time, and then there is a path gets created between the person and the beyond. So all learning that drips through me after that first experience is also a Satori because it happens only in meditative state. I need not have to sit in the usual posture of meditation because I practiced and reached through awareness or mindfulness meditation. So during any act that I am doing meditatively fully immersed and for a moment the ego dissolved and the existence drips its knowledge into me. Perhaps, you will not find it in any book etc.
In Arabic texts, and ancient sculptures too, they mention a ‘wisdom snake’. It is a snake making full circle so that the snake can eat its tail. It means when a person attains wisdom, he comes to this understanding that every person is at a junction of beginning point and end point of circle of life. In India we too consider that life is a ‘cyclical projection’ of God-said Vivekananda referring to Vedanta text in a lecture. [extended it to holographic projection (after one satori on it) in one of my posts to better understand it as per technology available today for young generation people].
Normal person is living life at periphery of that circle, and the inherent imbibed/embedded challenge set by God is to complete it in this life itself. All the restlessness or feeling of unsatisfactory achievement after achieving it, is due to this embedded system not delivering satisfaction from outer achievements. Only inner achievement ie ‘Wisdom circle completion’ is able to satisfy its condition. The moment it completes, the person falls from periphery to the centre of the circle. This falling is called as acceptance of Bhakti by God or Guru’s Kripa in Gyan Marg/meditation/evolutionary mysticism. It happens on its own because one can only able to satisfy the condition when the end point meets the beginning of the circle. This falling for first time is called ‘SATORI’, in Zen. Still one is living at periphery but as and when this coincidence of beginning meeting the end happens, there drips the knowledge from beyond. All other Satori experiences are like that.
Nirvana is completely leaving the periphery and permanently sitting at centre of circle, and to give lectures to disciples like Osho did, he make himself available at periphery because we can be communicated by sitting at our level. Still he used to say that those who are enlightened disciples are getting my guidance in silence too. Buddha’s transfer of light(lotus) Mahakashyap was actually opposite, Mahakashyap in that moment was able to drop permanently at centre without Buddha speaking any word. Later Buddha gave him the Lotus flower as a mark of his endorsement to his achievement.
So the invention of such circle with centre gave another number in mathematics as ‘शून्य’ or Zero. That time all mathematics was geometry based, and no one can draw a zero. It will have a width and length whether it is of nano sized. All measurements begin with Zero but no one can draw it. Why? Because the zero is where the infinite meets! Both are undefined but they exists, and human being is that junction of Zero with Infinity. You have to lay down yourself to draw a zero, but you are the person drawing it! So it is undefined. On attaining Nirvana (Satori in Mohammedens, Christians and Jews) the person, zero till date, says I am the infinite. अहं ब्रह्मस्मि or the master praised ‘तत् त्वम असि श्वेतकेतु’. The one who is measuring is also a number in our mathematics. To let him remember continuously that the zero is where the infinite meets, it is added to mathematics! Simple.