Alcoholism, or active alcoholism, tends to give you this “getting away with it” feeling. It’s a weird illicit thrill, like you are slipping something past everyone. The idea that “nobody knows how much I drink” gives this odd secondary thrill that was almost as powerful as the alcohol itself was, at least for me.
One of the big things that pushed me to finally stop was that people started calling me on it. Friends, relatives, servers, complete strangers, all said things to me about how much I drank. It became clear that other people did know.
In sober hindsight, I was like the kid with chocolate all over his face saying he had no idea where the candy went. Adults may choose to punish him, or may choose to ignore his lie. But there is no way that they don’t know what he did.