When we feel foggy, we're clogged. There's too much that has come our way. We have trouble processing everything mentally. Too much stimulation equals fog. Effectively, we shut down when our mind can't take in even one bit more.
Dreams, that wondrous state in which our conscious ego recedes and our deeper self comes to the fore, help to sort through the clogs. A depth psychologist, Dr. Antonino Ferro, wrote in his book, In The Analyst's Consulting Room, depth therapists dream of their patients so a to work through clogs, emotions that get in the way of therapeutic understanding.
Dreams get us through clogs that get in the way of understanding ourselves and others. Someone told me that they dreamt of a close friend who reached out a hand, asked for help. The next day they received a call from this very person. Because of the dream they set aside their many duties, concerns and fretting that could clog life energy, and reached out to a friend.
Dreams unclog the mind so we can reach out when appropriate and reach in to self where deep waters run clear and, in the words of Dr. Antonino Ferro, "we are struck by the sense of well-being that follows such dreams, to the point of waiting and hoping for them to come..."