I've just added a few more of Derek's sayings (in the "gadget" on the right side of this page).
One of my favorite ones is this:
"Your feelings do not matter. Your feelings do not produce success. So
focus on what does produce success. Suck it up and drive on. Hammer it
This goes along with something he told me once when I was struggling to reach what I thought should be the next step in my training progress:
"Instead of thinking about how bad you hurt, or how tired you are, or whatever things are dragging you down, think about the positive. Think about the reasons you're doing this. Focus on how you're going to succeed. Focus on the good things you'll accomplish."
That advice helped me then, and I'm using it to help me again now, as I'm re-focusing and re-committing to my training.