One of the very best feelings in the world is hearing someone laugh, knowing you made them laugh, after you just helped them when they were crying.
AND ON THE CONTRARY
One of the very best feelings in the world is when you're crying on someone's shoulder(or something) and they make you laugh. Like, whatever it was that made you cry, you know it will get better. Or if it was something good that made you cry, then they're there for you anyway.
The second one happened to me the other day, I was crying my eyes out, but over something good. And my friend let me cry on his shoulder and by the end we we're just dancing to the music, still holding onto each other for dear life, basically. And while I was crying he had said something that made me laugh, and it was such a great feeling.
The world is full of good, you just have to open your eyes and see it.