Actually the guidelines were plucked out of the air, based on when some people first start to show signs of ill affects (and these vary).
Would find a link, but can't think where to start, but there have been many interviews and investigations into why the limit is set as it is... Going over the limit does not mean you will die, or become ill, or are an alcoholic. It's based on the average quantity where ill affects start to surface on some.
It's not denial. I drink more than gov guidelines some of the time. I watch my intake but don't fret if I have all weekly units on one good night, or if I've had a glass (small) of wine every day for a month...
Interesting point though Hecate when I know I've been overdoing it (usually after a holiday) I don't talk about it so much, so I think it's totally logical that you were careful way before you're problem got out of hand. I know that because I LIKE drink, I am probably more at risk of developing a problem than someone who doesn't. I am careful.