Perhaps one can learn from others' mistakes.
I think this one is better of the two
"I see that you notice that I wear glasses. Well, it was to be. I've not only grown old and gray, I've become almost blind in the service of my country." - General George Washington
"There are times in your life you'll be required to perform an exceedingly difficult task to the best of your ability, regardless of your perceived capability. Mental toughness is what will carry the day during these times. In other words, you suck it up and do what you have to do." - Razor