Probably when I start getting sick. That's when I've had too much. Falling over drunk was fun though.

I remeber one time I was so whacked out of head, I went to 7-11 and got a huge pop for my mix. I was already drunker than a skunk, so when I got back in the car, I had Pepsi, and mixed in some Jim Beam. Shortly after I poured a beer in the mix to flavour it up. It tased fine to me at the time, so that's probably another time when you've too much to drink.