I observe a green leaf. During this process I entangle with the environment because photons of light reach the eye, cause electrochemistry in the brain followed by vision.
When my eyes are closed and a green leaf is present i do not experience it , because photons of light do not reach my eye. I am no longer entangled with the photons/environment.
Experience occurs with the entanglement process of the observer with the object of observation.
If we understand entanglement we will understand subjective experience.
We make an image of the object in the mind. When decoherence occurs there is disentangling of the observer with the object , then the image in the mind and the object fades away from thought. A memory is created when decoherence does not occur fully.