School colors line the streets of D.C. every weekend.
Not all schools, of course. Just the Good Ones.
First, we have the high school tee. In a small town, if you see a grown man, one not old enough to be a grandparent, wearing one of these it usually means, "Yeah, I'm 30 and I have a kid in high school." Or, "My best days are behind me and now I live in my mom's basement." Sometimes both.
In D.C. they're all from boarding schools. Wearing the tee means, "Yeah, I didn't get into an Ivy."
Then we have the minor eastern seaboard colleges. (Do they ever graduate anything that's not blond, btw?) I won't name names. Both because it's rude and because I still don't completely understand the hierarchy involved. Is Holyhoke better than that one down in North Carolina? Whatevs. They seem to know.
Finally, we have the top schools. Of these, only Harvard grads (and parents and cousins and grandmas of Harvard grads) will wear the tee in public (Sometimes even, it seems, as part of a business casual ensemble. Which even a hick from nowheresville like me can tell is PRETTY TACKY). Maybe you'll see an occasional Columbia or Stanford. Never a Yale. This is because the classy way to advertise your school pride is to wear the colors. Which are always gaudy and not something a normal person would combine. That way only everyone who has ever heard of Princeton will know why you're wearing tiger striped socks.
What you don't often see are the Big Ten school sweatshirts that blanket the ever-increasing middles in the middle of the country. Everyone has at least a few school tees where I'm from - most of the people wearing them didn't even go there. It's how you advertise which sports you're in to (basketball is Indiana, football is Ohio or Michigan, Wisconsin just says saddddd...) Or where you grew up. But no one wears them here.
This was weird to me when I first moved to D.C. It became less weird as more people reacted to my school with, "Oh. Uh huh. So where is that again?" (In the STATE with the SAME NAME, maybe?)