You were probably speaking to the techie of the whole shop at least he knew what a graphics card was.
Most of the desktop computer sales reps seem to work on the principle that if its a beige coloured box it will do the job for you. If its black its a high performance machine. I am surprised nobody has produce a special PC world super high performance computer in a red box stick, a couple of hologram stickers on the front and the sales reps will be licking them everytime they walk by.