A lecturer teaching medicine was giving a classoom observation. He took out a jar of yellow liquid. "This," he explained, "is urine. To be a doctor, you have to be observant of color, smell, sight, and taste."
After saying so, he dipped his finger into the jar and put it into his mouth. His class watched in amazement, most in disgust. But being the good students that they were, the jar was passed, and one by one, they dipped their finger into the jar and put it into their mouths.
After the last student was done, the lecturer shook his head. "If any of you had been observant, you would have noticed that I put my second finger into the jar and my third finger into my mouth."
A philosophy professor walks in to give his class their final. Placing his chair on his desk the professor instructs the class, "Using every applicable thing you've learned in this course, prove to me that this chair DOES NOT EXIST."
So, pencils are writing and erasers are erasing, students are preparing to embark on novels proving that this chair doesn't exist, except for one student. He spends thirty seconds writing his answer, then turns his final in to the astonishment of his peers.
Time goes by, and the day comes when all the students get their final grades ... and to the amazment of the class, the student who wrote for thirty seconds gets the highest grade in the class.
The psychology teacher had just finished a lecture on mental health and had proceeded to give an oral quiz to the students. Speaking specifically about manic depression, the teacher asked, "How would you diagnose a patient who walks back and forth screaming at the top of his lungs one minute, then sits in a chair weeping uncontrollably the next?"
A young man in the rear of the room raised his hand and answered, "A basketball coach?"