Nobody can see things clearly when they are surrounded by funhouse mirrors. It's ALL distorted.
The power of suggestion is, well, powerful. People can be suggested right into believing what isn't true at all. That's the whole basis of hypnosis, ya know?
Keep questioning and challenging the truth of those thoughts. One tip, though. Don't count on succeeding in convincing anyone else that what you are thinking are delusions. They have a vested interest in your continuing to believe the delusions. So don't expect the alcoholic, or those close to him, to congratulate you on your insight.
WE, on the other hand, will jump up and down and yell ATTAGIRL every time you see what a lie one of these thoughts is.