It's no one's fault but our own.

“The fault, dear Brutus, is not in our stars, but in ourselves.”
-Cassius

This is a quote that I haven't had for very long, but I was instantly struck by it. I was reading "The Fault in Our Stars," by John Green. You can find a summary here. I think this is possibly his best book yet. He, of course, derived the title of his book from Cassius.

The word stars could imply the future, and I think that is what Cassius was getting at. In my opinion, this quote is saying that it's not the future we should be looking at.  Cassius is saying that we should think not just about the present, and what we are doing with it. But what we are physically doing with ourselves. The problem isn't our future, the problem is ourselves. It's not, we have to make sure our future is secure; it's we have to make sure we are secure with ourself. By changing ourselves, we are changing our future.