You need to be continuously striving to go beyond your comfort zone if you want to be good at something. Screwing up should not be a barrier to success. It should be embraced as an positive outcome of learning and trying something new. If you are not failing then you are not trying hard enough. No one has ever learnt to drive a car without stalling.

The article by Dr Heidi Grant Halvorson outlines her thoughts on why giving yourself permission to screw-up, could be the best decision you make.

http://99u.com