Good things. You'll find em one day

The best time of the day
When the sun sets 
You knew in the beginning it wasn't here to stay
Good things always have to end
That is what on the world depends
People laugh people cry
And everybody wonders why
It's because before them there were good things
So of course it had to end
So they laughed and eventually cried
The good thing eventually died
But there's a catch to this simple concept
Not every single good thing must end
Some things must prevail
Those are the things of which are on a greater scale
Nothing of which we can comprehend
For the simple reason that they do not end
So what I've learned here
Is don't shed a tear
Because some good things come back
And others never leave
So keep your smile
Let it hang around for a while
When it's gone remember itll be back some day