Critics have value, too.

But this is a good quote nonethless, plus an intro from Dean Karnazes (from his blog at Runner's World):

What constitutes a life worth living? Is it high achievement? What I’ve come to believe is that more than anything, it’s having the courage to try. Perhaps no one has stated this more eloquently than Theodore Roosevelt when he wrote:

“It is not the critic who counts; not the man who points out how the strong man stumbles, or where the doer of deeds could have done them better. The credit belongs to the man who is actually in the arena, whose face is marred by dust and sweat and blood, who strives valiantly; who errs and comes short again and again; because there is not effort without error and shortcomings; but who does actually strive to do the deed; who knows the great enthusiasm, the great devotion, who spends himself in a worthy cause, who at the best knows in the end the triumph of high achievement and who at the worst, if he fails, at least he fails while daring greatly. So that his place shall never be with those cold and timid souls who know neither victory nor defeat.”

I thought of a funny saying that I just wrote: "don't forget to put the 'for' into 'effort' . Because if you don't do that, then you're just ef't. (it makes sense if you say it out loud). .