Absolutely everything!
From the front desk staff to the Hertz in FBO Rental Car desk CSR to your wonderful and kind line service. My experience was smooth and profoundly normal. Normal meaning interactions with eye contact, firm handshakes, we are happy you are here, and calm actions that only come from professional knowledge and professional competency.
Professional Knowledge: Has to be acquired the hard way. Professional knowledge requires constant study. Professors, engineers, architects, lawyers, solicitors, doctors, all study their professions continuously. They all contribute to magazines, to newsprints, to all manner of publications. You have to study all of your life.
Professional Competence: The ability to make up your mind, make a decision, and accept full responsibility for it.