When we wake up in the morning, it is a general experience to say ‘I had a nice sleep last night’. The body is rejuvenated and there is a freshness in mind.
Here is what happens when we wake up. The mind in the dormant stage or biija avasta (Seed in Sanskrit) rises up. The first thought that arises from the mind is ‘I’ thought. This thought continues till it slips into sleep. After I thought, sense organs starts functioning. Sense of touch kicks in which associates ‘I’ with the body. Thoughts which created deep impressions start rising in mind and ‘I’ gets identified with those thoughts. In this process, slowly when you see your wife, a thought that I am husband appears, like wise a person is created from the thought.
During initial hours of wake up, mind is calm and there is a experience of fulfillment or bliss. Mind is in the state of Satva Guna. Mahatma’s suggest to contemplate during these hours. Generally in the morning hours we prefer to meditate.
It is pure ignorance to say that ‘I woke up’ or ‘I slept’. By the law of karma one has to wake up to experience the world and suffer in it. Person identifies with the world(Jagath) and performs activities to satisfy himself(pleasure / pain). During this phase he accumulates lots of impressions in mind(vasanas) and continues to repeat those activities. Hence, Bag of vasanas are accumulated due to ignorance and mind (Sukshma sharira or subtle body) has to rise and associate with a body.
Very hard but true fact, just like a filament in the bulb cannot withstand the electricity after certain period of usage, body also after particular period of sustenance cannot withstand the Prana shakthi or life. It fuses. But, subtle body is still there with all those impressions and very efficiently takes another body to experience. In this Journey no mistake can happen because it is Ishwara shrusti.
“mamaivamso jiva-loke jiva-bhutah sanatanah manah-sasthanindriyani prakrti-sthani karsati”
Lord Krishna says in BG Chapter 15, The living entities in this conditioned world are My eternal. Due to identification with sense organs and mind they trap into never ending cycle of samsara.
Hence it is advised in shastras (Vedantic Teachings) that it is always very important to reduce body mind identification and remain a witness to reduce cycles of birth and be liberated.