Why Does All Good Things Come to an End?

You all heard the saying, right? A good thing never lasts, it has to fall? Well, here's my question, why does it have to always end? Why can't everything stay really good forever?
I have come to one theory about this. In life we need balance, and too much of a good or a bad thing could perhaps disturb this balance of everything. You know, like too much of anything isn't too good? I guess it's like ying and yang.
To me, life is like a game of cards-completly unpredictable. You never what is dealt until after you look at the cards, and you never know what card you are going to get next. So enjoy the card you're on, if it's a good one. Enjoy every last bittersweet moment, because you really don't know what is going to be dealt to you next. Live like Rose and Jack on the Titanic, like every moment is your last. Because, for all you know, it just might be.
And for the bad times? Remember that these are the times that make you strong. Remember the good times, the sunny days. They will get you through the storm.
So to whoever is reading this. Live like you are dying.