If you think you drink to "cope" or to deal with stress, etc, recall the last time you had a bad day at work and decided to go to the bar afterward. Do you remember what you were feeling as you were driving to the bar? I'm willing to bet that you were so focused on anticipating that drink that your mood was elevated, even before you had your first drink. In other words, even while your BAC was zero, the original reason (excuse) for drinking became irrelevant. So, ask yourself: if you were already feeling good, did you really need that drink to cope, or was it your Beast that wanted a drink?
See "Figure 4: The Feeling of Alcohol" on page 183 of "RR: TNC" for a nice illustration of this phenomenon.