The feeling of depression after going to a really good concert. Usually involves depression over the fact that your lives purpose is now fufilled after seeing your favourite band. Also can involve depression over the fact that you might not see that band for a long time. The best remedy for post-concert depression is going to shows with local bands, as they tend to play more often and will keep you sustained.
"That concert was so good!"
"Yeah but now they won't be back for a long time."
"Oh man, that blows...I've got like, post-concert depression now!"