Failure is the concept of not succeeding when making an attempt at doing something. Nothing more, nothing less. If you do not succeed at that particular attempt, it doesn't mean you made a mistake...it just means you were unsuccessful....THAT TIME.
For example, I am a huge Atlanta Braves fan and love watching the game from the 755 Club which is named in honor of baseball great Hank Aaron's record of 755 Home Runs. Everyone focuses on the 755 home runs, but he also struck out 1383 times (nearly twice the number of strikeouts for each homerun he hit. Unbelievable!!!). Does that mean he "made a mistake" 1383 times? Absolutely not. He simply did not succeed during those attempts. I think his lifetime batting average was around the .305 mark which means that 70% of the time, he was FAILING...NOT making mistakes.
My point is that people have a tendancy to beat themselves up for "failing" and equate it with making a mistake which only causes them to make fewer and fewer attempts...which ultimately leads to quitting. And it is definitely much more painful in the long run to to fail because you quit or simply gave up rather than simply enduring any short term discomfort that temporary failure causes.
BTW, Major League Baseball's leading strikeout king is none other than Reggie Jackson. He didn't have too bad of a career did he?