When you're so tired that you start acting all loopy, giggling at everything, making no sense, etc. Also referred to as being "sleepy-drunk."
Man, you should have heard the ridiculousstuff that Tiff started saying around 2AM. She had the winkies and she couldn't stop giggling at the word 'buttons.'
Nudists over the age of 29 usually develop tan lines under the crease of their butt. When standing still they cannot be seen, but when someone is walking away the untanned regions will flash in alternation.