It's weird. The world never stops. No matter what happens, or how much you think the world is caving in it really doesn't stop. It won't stop for me. It won't stop for you. And it won't stop for any stranger that you pass on the street. I think this tells us something though...
We as people cannot stop. Ever. Especially not with our goals. When we stop, nothing else stops, and it just brings us behind. When you're ahead, you're ahead because you didn't stop. When you're behind it's because you decided to see if the world would stop for you. But, I know it didn't. And you know that now too.
So don't stop when you're tired, or think it's too much. Keep going, because in the end you will thank yourself.
When you reach where you want to be, that is when you will know you can stop. Simply stop, and let the world keep going while you are still.