If you’re said to be “feeling blue,” it means you’re down in the dumps.
However, we don’t think it’s fair. Just like the pants pockets, the tie is real, so you will have to know (or learn) how to tie it if you want to wear it traditionally. As far as we know, the color blue came to be associated with sadness because water is blue, and tears are made of water. You could also wrap it around your wrist or something, but we’re not sure how well that would work.