Is 'I'm An Inexperienced Bartender' Stamped On Your Forehead?

Remember Woody from the television show ""Cheers""?What was it about him that tipped you off to his inexperience behind the bar? Was it his shyness, gullible personality and not being too wise to the ways of the world?Yes, but those traits weren't about bartending. In real life, being the inexperienced bartender, you know exactly what tips off your customers.