Here’s a hypothesis I have been trying out lately:
If you aren’t failing and getting rejected a lot, you aren’t being ambitious enough.
It’s a point of view that helps keep a person going when they are applying for job after job, with no interviews so far. It could also be of some comfort to those who had solo Valentine’s Days.
And, it might even be true, to boot! If we are going to expand ourselves as people, we need to do things which we feel uncomfortable about: give lectures to more people than we feel at ease with, play Starcraft II (or your piano) at a higher level of difficulty than you feel comfortable with, take on an ambitious project, submit work to journals that might reject it, give an honest answer to a challenging question in hopes that it will be well received…
Depending on the field of endeavour, it seems fair to say that you should be failing 90% of the time – with ‘failing’ meaning that you think in retrospect that you could have done something better, in undertaking whatever you just did (whether you succeeded or failed). If more than 10% of your attempts are going off absolutely perfectly, you should probably try something more challenging.