Failing by default

I've just read a quote attributed to J K Rowling in which she said something about not being able to go through life without failing at something and that if you don't fail, you're probably living your life so cautiously you fail by default (my interpretation and paraphrasing). The concept started me thinking. Does that mean you have to fail at things regularly in order to be considered to be living life fully? I would find that demoralising.

I like to think that we learn how not to fail as we go through life; we learn how to do things better so our chances of success increase. We discover our strengths and weaknesses and exploit one and improve or compensate for the other. Of course that could also mean we also learn how not to expose ourselves to things we'll fail at; become more cautious. But is cautiousness a failure or a desirable skill?

I live cautiously. Any risks I take are calculated and manageable. I don't want to crash and burn - been there, done that, not going back. There are aspects of my life that I want to change and improve - I just don't have time to arrange it right now. Generally though, my life is where I want it to be. I'm working full time in a job I love; I'm studying in an area I enjoy; I'm writing, which I adore; and I'm even submitting work occasionally. I have family and friends - all really special people I'm proud to know.  Why on earth would I want any of that to fail, just so I could say I 'live', at least according to the definition in that quote?