What do you call a sad cup of coffee? A ...

I cover your head, but I am not a hat. I am often attached to a coat. What am I?

A safe place to go when you need to lay low, or perhaps a tree fort you made with your bro. A spot to remain to not be seen, or even a place where a villain goes to scheme.

I may keep a fence standing, or keep your friends updated.

I keep things in; I keep things out. A click or clack means I’m about. A memory of one’s lost past; A haircut, maybe first or last. These two things share a name alike, And don’t forget one for your bike!