Yesterday while attending a gathering of football fans watching their favorite team there was a ceremonial passing out of the "yellow and black" jello shots. "Yellow and black, yellow and black, take one." Is there alcohol in it? Yes. Then no I don't want one, you know I don't drink. "Well you can have one can't you?" NO, I can't have any. A half hour later, do you want one this time. I just gave that look like, "You're kidding me!"
Why do people relapse? I don't know. Because my thoughts are that if one "relapses" it's because they wanted to relapse.
AND - Because they were not/are not educated enough on addiction/alcoholism, it's cause and effect and the propensity of an alcoholic to always "be" an alcoholic. The last part of that goes along with the educational aspect of the entire dilemma.
There is no such thing as a "dry drunk". I've searched medical publications for it - it isn't there. Do not let the dogma of any organization fool you into thinking a "relapse" is inevitable for anyone who does not subscribe to certain behaviors as written. Unless one is given factual evidence about how alcohol affects them in a true medical sense, they may never fully comprehend it. And until they do, they are more subject to "relapsing". Don't let anyone lay that "dry drunk syndrome" nonsense on you to give you the excuse you want. Learn about it, and decided whether or not you wish to 'get better' by refusing that drink - or any alcohol laden food product.
Many people 'relapse' because they believe they are expected to relapse. And that is a shame. Relapse is NOT a part of getting sober. Getting sober is and should remain a one time event.