Rocks in your head.
My sister was told that when she went through her divorce. "The rocks in your head no longer match the holes in his head." I think that applied when I broke up with tobacco. The science of it. My brain has nicotine receptors and cigarettes contained nicotine. I just googled that and the affect on human function is all there in print. I did read that nicotine was useful in people with Parkinson disease. So quitting is about changing the brain. One site said that it takes one month for the synapses to really settle down. It is early days in my quest to get off caffeine. Ten days only. But I notice that my bed is easier to make in the morning. Not so much thrashing around. Related? Also I have not had a craving for chocolate. One is too many and a thousands not enough. So I intend to invest in a rock polisher. Healthier and wealthier.