I don’t know who said it but I like it – “ball players need a short memory at the plate.” I used to be a softball player, for many years actually and that statement is very true to the mental part of the game. And as you grow older and learn more about sports and life you inevitably stumble on the fact that the mental part of any sport is far more crucial than that of athletic ability. Not to discount athleticism but rather understand the support mental strength provides an athlete in training and competition. 
So what does ‘ball players need a short memory at the plate’ mean? To me it means that focusing on my past failures won’t provide me success in my current endeavour. But, and this is a big BUT, that is not to say that we should ignore our failures, in fact they are great lessons. Any good athlete and any good coach review the players performance to see what went wrong and how best to correct it for the next opportunity.
Business is no different, let’s take Target coming to Canada as an example. Their expansion efforts into Canada seem to be a sizeable failure. And I am very curious to know what lessons they learned from it versus what blame they are assigning for it.  From the outside looking in it appears that they were unprepared in some ways and over invested in others. Perhaps they assumed that Canadians are just like Americans in terms of shopping habits? Maybe they looked at the amount of Canadians that shop in American Targets and thought that profit was transferrable to the Canadian market.  I have a hard time thinking a company as successful as Target didn’t do some hard-core analysis and preparation before coming to Canada.  Just like athletes analyze and prepare, but sometimes things go wrong. The key is to focus on using the wrong to make you better. Focusing on the failure will only add fever to your fears and doubts because that voice inside your head is dying to tell you how you will fail again and again.
Having a short memory at the plate is about not dwelling on the bad feelings of striking out or being hit by the ball. Great athletes don’t dwell on what they did wrong, they use it to focus on doing it right next time or doing it better.
If Target focuses all their energy on the demise of the Canadian expansion instead of on why the Canadian expansion found demise then they are destined to fail again, and perhaps again and again. 
As a leader if you are focusing on the flaws and the mistakes of your team instead of using them as teachable moments you are missing the ball. I believe it is imperative to the development of our healthy ego and self-perception to limit our wallow time. I believe that sitting in your own defeat will fill your days with the same. I believe that every failure is an opportunity.
Unless you are perfect, and I challenge you to provide evidence of such, you will make mistakes. And those mistakes can be opportunities if you choose that. I can’t imagine that any high caliber athlete is shocked when their performance is lack luster. That you would have to point out to them that they missed that goal, or that time or that touch down. The same is true for your team, most of them will be very aware that they have screwed up. How motivating is it if you focus on their failure? What if you focused on how that failure can make them better, which in turn can make your company better? What if you focused on the value of the new knowledge brought on by the error?

I’m not saying all mistakes are worth championing, what I am saying is that I can’t see how further defeating a defeated person is helpful for you, them, your team or your company. It takes attention and willingness to accept blame for the lesson to actually be a lesson and not a repeated error.