Advance, at least the one I work at, has a pretty high standard for working. One of the big reasons I was hired is for what I know about cars, which pales in comparison to what a lot of the other guys know. In fact there is only one person in the entire store who doesn't know much.
We've got a few who have hardcore knowledge of cars, including the old ones. Even knowing how to look up a carburetor just by the number stamped one an old one picked out of a yard from a vehicle the customer forgets the year make and model of.
We look down on Auto Zone for the very reasons you just mentioned: completely clueless plus generally lower quality parts.
As for the job, I enjoy it. Great people and genuine car guys. A few of them are Jeep modders who go hardcore offroading. There's a nice sense of pride everyone has working at the store, and I have it too. So that's cool.
All stores are different and so will be the amount of knowledge employees may have, but next time you run into a problem like that, try asking for a Parts Pro, they're the most knowledgeable people.
It's a genuinely small world out there. One guy who I've become friends with told me that he used to live with a room mate in what is now our house...so I got some interesting history on our place. Then yesterday I found out that one guy was an automotive instructor at my old high school, and so in freshman year we met! Friggin' crazy.