What Would You Do If You Knew You Could Not Fail?

I came across this query the other day, "What would you attempt to do if you knew you could not fail?" I don't know. Interesting concept, though.  Fear is interesting.  It is a motivating force in our lives whether we like it or not.
Sometimes fear can be a good thing.  It can save your life by preventing you from doing something stupid, but as a general rule, it hinders us.  Even more hindering than fear, anxiety, fearing something that hasn't happened, fearing what could go wrong.  Living life based on what could go wrong is not a happy way to live. Would I live a happier life if I knew I could not fail?  What would I do? 

Maybe it's not a bad thing to know you may fail; maybe it's only bad if you do not try because you are paralyzed by fear of failure.  

I'm on track to go to grad school even though I know I could fail.  I keep dating people even though relationships have failed in the past and will likely fail again.  I accept that not every venture I have will be successful, but as JK Rowling says, 

"It is impossible to live without failing

at something, unless you live so

cautiously that you might as well not 

have lived at all - in which case 

you fail by default."