My theory is that before going to sleep different parts of the brain shut down not in one single moment, but at different moments. Therefore before sleep some p

My theory is that before going to sleep different parts of the brain shut down not in one single moment, but at different moments. Therefore before sleep some parts of the brain is already sleeping. That would explain why so often ideas that seem good before sleep look silly when you wake up. As in this case, maybe before sleep parts of the brain that produce depression shut down sooner and "temporarily cures" the depression.