Nothing makes me feel more like an outsider than being asked "Where did you go to high school?" For I didn't go to high school in STL. It's even a running joke to natives. They know that the question is so overused in STL. But they use it anyway. They'll preface the question by saying, "OK, the big question..." or "I know this is such a St. Louis thing, but..."
High School Schmigh School! How about college? Asking about high school only means you can't leave that joyous time in your life. Get over it. Move beyond high school. How about this? Before you ask that question, try asking if the person is even from St. Louis. You might have the answer you're looking for w/o asking the "big question".
Knowing what someone's high school alma mater is is trying to figure out if you'll accept them or not. It's not a way of bonding. Odds are, if you didn't know them and they went to the same high school at the same time, you didn't want to know them in the first place.
St. Louis is very territorial for this reason. It's hard to break into it if you know no one. I moved here from the Cincinnati area. I knew no one. Especially in the business field I was previously working within in Cincinnati. I had the hardest time gaining acceptance as an outsider. Always the question. I feel like I disappoint when they come to find out I didn't school in STL. I also feel like they didn't read my resume since it clarifies that point as plain as day.
St. Louis, for many reasons, is very territorial; very incestual.