Or your fancy hat?
Don't even know what the derby is all about? (Because it is a lot more than just a horse race)
Here is a nice montage to watch if your wondering, or if you can't make it to Louisville, Kentucky for the festivities:
You should go at least once to experience it. Put it on you bucket list.
Oh, and here is some great info for selecting your horse. If you're into that sort of thing.
Missing My Old Kentucky Home,