What does "The Road to Hell is Paved with Good Intentions" mean?

[Sacred Fool]

Can you stay on track by staying humble?
I always ask for the Universe to keep me humble.

  
Well, the problem is that it's hard to know when you're inching towards selfishness, that is, it's hard to catch yourself sometimes.  In my view, all we can do is try to be honest with ourselves, to try to cleanse and inspect ourselves for that which no longer serves us from time to time.