No question, a trip to the parts store can be daunting. I have quite a collection of old parts catalogs, due to having spent quite a few years in the automotive/heavy truck parts industry. It is always good to have part numbers on hand, whenever possible. The mentality of the retail parts industry is to have a computer catalog system replace the knowledge of a seasoned parts person (who often is mechanically experienced as well). They can keep their labor expenses down in this manner. They hire store managers who often don't have a shred of automotive knowledge, they just have management experience (a local AZ has a manager from the fast food business, no car experience)--it's a bit scary. I only use these places in an emergency, as I can order my parts from Rock Auto/online and save a lot of cash and potential heartache. The only downfall is if you have a warranty issue, but I've yet to have an issue after all these years. Of course, there are still some parts stores that are more geared towards automotive professionals, and they typically have more knowledgeable employees.
