It's an old expression, but in general, it's a good reminder that whatever you are going through, it's not the end of the world and you will be able to get through it. And it's the way I feel most times when I am struggling with something. I try to tell myself, "you endured so much more before and you were all alone then."
Now that I share my life with Ric, it's easier to convince myself that I can get through anything. I have a partner, someone who truly has my back and supports me through anything. And that makes all the difference.