What induces the obsession and phenomenon of craving?

What happened to me was in my late teens and early 20s I binge drank alcohol so regularly I developed a psychological addiction to the effects of ETOH. As far as I know, I never became physically addicted and I know this because the day I stopped drinking I quit cold turkey with no physical withdrawals that I noticed. But the psychological addiction became a permanent part of my mind and I've had daily cravings for alcohol ever since, usually the cravings are at their most intense at night, which was when I used to drink. Over this year I started drinking occasional shots of vodka, then over the summer this year I drank beer every weekend and often one night on week day nights. Now I've had to stop drinking due to some unfortunate circumstances, and now I crave beer all night every night and it's become more intense than it was last year when I was still abstaining from all alcohol. As far as I can tell, the cravings are permanent and consuming ETOH will intensify the cravings because it's like giving the psychological addiction in your brain a "nosh" of what it wants. Physical addiction to alcohol can be cured, but the psychological addiction is permanent.

This is why I follow the rule of "one is too many and a thousand never enough". I manage my cravings well... unless I cave to them even a bit. I can't possibly have ONE beer. It's like poking the asleep lion with just one stick.