I once had a friend that was a barber. He used to have people come sit in his shop all day, and chew the fat, just like in the movies. Half the time they would fall asleep, and start snoring. My friend became really good at being able to diagnose sleep apnea symptoms on the spot, on account of how they wounded while they snored. He would tell them to go to the doctor, and he would tell them exactly what to say. He became the most famous barber in the whole town because of that, and was able to retire at a very early age.