At about 60 hours, I start seeing bears, particularly if I'm driving. By 72, I'm beginning to discover their beautiful language.
LOL! Once I didn't sleep for a few days straight, and then I got a few hours sleep one night. When I woke up the following morning at the sound of my alarm, I thought the smoke detector was going off. I leapt out of bed and unscrewed the light fixture in the hallway, burst into my mom's room with it in my hand, and yelled, "I can't turn off the FIRE ALARM!" Lack of sleep does some crazy things to your brain.