It’s a knitted coffee cup sleeve. It keeps your fingers cool, your latte hot and your sense of social righteousness toasty.
You say you don’t need one. You say it’s silly. You make smart alecky remarks when you see mine, but secretly you are filled with envy and wish you had one of your own.
There’s no need to be sad and twisted inside: just go get one. It’s a little, happy sweater for your Starbucks and it will make you happy and sweatery too.