You read that right you have permission to fail. Do it. Try and fail. That is a good thing. Why, because you tried. Now the key is to get back up and try again.
Many famous people (and many more not so famous people) have failed more times than you can count on your fingers and toes but in the end they were successful. Why? Because they were okay with failure and they kept trying, even after they failed.
First, let's talk about failure. That term is not really appropriate, but I will use it because it works. Failure is relative. If you are trying to lose 50 lbs and you gain two pounds in two weeks that might not be considered a failure if you lost four pounds the week before. Failure in one occurrence or one day (I didn't avoid the cake and went over my calories) might not be considered a failure (if you stayed within your calories for five days earlier that week). When you think you failed, go ahead and get upset. Vent, curse, scream or confide in a friend. Then after you do all that, try to look at the big picture. Did you fail one time out of five or ten tries? Did your failure get you closer to figuring out how to succeed? Try to look at your failure relative to all of your goals, not just one.
Second, let's talk about what happens after a "failure." After you let go of being upset or angry with yourself did you learn something? Are you more challenged to keep going? Are you prepared to motivate yourself to try again? To be successful in the long run you must try again. Trying again could mean another failure and another, but if you are prepared to focus on your goals and keep going (keep trying) then eventually you will succeed. The key is to try and learn from the failure, What triggered you to go awry? What could you do differently next time? If you are trying to lose weight and the failure was to avoid the cake and you went over your calories, why did this happen? Was the cake tempting because you had to pass it in the break room five times that day? Was it tempting because you skipped lunch or left your mid-afternoon fruit snack at home? What could you do next time to avoid the cake? If you think about what to do differently next time that will help you succeed.
So give yourself permission to fail. But make sure you learn from that failure and try again.