Over fifteen hundred years ago, on an island in the North Atlantic, St. Stupid Apparel rounded up all the team colored merchandise and drove it into the sea. He then replaced all the items with stuff you could only wear one day out of the year (without looking like an asshat).For more recent developments in St. Stupid Apparel's Day, please visit Simon On Sports. He has extensively chronicled these recent crimes against team branding and aesthetics. You can even vote on the most egregious!
Now go sneak out of work and grab a Guinness. And bring your green hat.