I can always tell when I've had too much to drink because I start thinking through ideas which a sober mind would disregard. I used to think I was "thinking outside the box", and working through problems of life. The next day, I was often glad I had my cellphone off, and my email closed during my binge drinking session. Many of those ideas were stupid.....but about 10% proved worth looking into when sober. Nothing beats a clear mind for decision making.
chip