When you talk to a mechanic he will mention ball joints, tie rods, starters, crankshafts and so on. A body man will talk about rocker panels, quarter panels, fenders, floor boards, and so on. A business man will talk about R.O.I., pre-tax, revenue, and more.
What it comes down to is one simple fact. Each profession has its own terminology. Once the person gets used to speaking the language of the profession he forgets that not everyone speaks the same language. When you talk in certain terms all day long it can be hard to realize others do not understand what you mean.
Most times if you just say I do not understand. Can you explain to me what you mean ANY professional will be glad to try to explain it more simply so you can understand. But if you do not say anything they think you understand the same words they use all the time.
It really is not about trying to impress you with their vast knowledge. It is about them being so comfortable with the terms they do not even realize others do not speak the same language. So ask them for a translation. I bet you will be pleasantly surprised at how willing they are to help you understand just what they have been trying to tell you.