I don't get this post concert depression y'all are talking about
And I've been to dozens of concerts
It's like being sad because it already happened so you're not looking forward to it anymore!
And you wanna relive it but you can't because it's in the past!
+ the memories you create there and everything, like wishing it never ended.
They are asking people to bookmark the page/save their comment, usually because they are predicting something that they are 100% sure will happen in the future. Then the people can go back and see that the prediction was true.