You are so exhausted and hungry that you start to have auditory and visual hallucinations. Your responses are delayed and distorted, comatose becomes comatoast. Once you do respond, if you do respond to social interactions, your response can appear completely irrelevant due to the lag (in fact your mind and body have separated and it takes some time for your neural networks to reach the cave where your processing mechanism is hiding). You are unable to make appropriate choices and when the barista asks single or double to reply double if not triple. Your overindulgence in caffeine, alcohol, chocolate and sex fail to return you to a normal state. There is no known cure for comatoast but the state does lapse and symptoms may disappear for months at a time (especially when you abandon your worldly possessions, quit your job and wander in tropical countries).
I was waiting for my friend on a park bench, (within arms reach of caffeine) it was a lovely sunny day, I soaked up the rays and stared blankly ahead, I was so tired I was comatoast.