Nobody thinks what I think
Nobody dreams when they blink
Think things on the brink of blasphemy
I'm my own shrink
Think things are after me, my catastrophe
I'm a kitchen sink
You don't know what that means
Because a kitchen sink to you
Is not a kitchen sink to me, okay, friend?
Are you searching for purpose?
Then write something, yeah it might be worthless
Then paint something then, it might be wordless
Pointless curses, nonsense verses
You'll see purpose start to surface
No one else is dealing with your demons
Meaning maybe defeating them
Could be the beginning of your meaning, friend
-Twenty One pilots

What they're trying to say, is that, when you feel that life has no purpose, and aren't living for anything anymore, then make something, weather it be, a poem, a song, a painting, or anything. As long as it matters to you, and you know what it means, then you have purpose, because if you die, then who else is gonna know what it means to you?