Obviously this is talking about writers, but I suspect that there are many things here that we can all either identify with or that we can apply to our everyday travails.

I love my rejection slips. They show me I try. 
Sylvia Plath

I would advise anyone who aspires to a writing career that before developing his talent he would be wise to develop a thick hide. 
Harper Lee

Remember: when people tell you something’s wrong or doesn’t work for them, they are almost always right. When they tell you exactly what they think is wrong and how to fix it, they are almost always wrong. 
Neil Gaiman

I discovered that rejections are not altogether a bad thing. They teach a writer to rely on his own judgment and to say in his heart of hearts, “To hell with you.” 
Saul Bellow

You must keep sending work out; you must never let a manuscript do nothing but eat its head off in a drawer. You send that work out again and again, while you’re working on another one. If you have talent, you will receive some measure of success — but only if you persist.
Isaac Asimov

By the time I was fourteen the nail in my wall would no longer support the weight of the rejection slips impaled upon it. I replaced the nail with a spike and went on writing. 
Stephen King

I encourage you to reject rejection. If someone says no, just say NEXT! 
Jack Canfield

For every accomplishment there were twenty rejections … In the end, though, only one attitude enabled me to move ahead. That attitude said, “Rejection can simply mean redirection.” 
Maya Angelou

Rejection has value. It teaches us when our work or our skillset is not good enough and must be made better … Rejection refines us. Those who fall prey to its enervating soul-sucking tentacles are doomed. Those who persist past it are survivors. Best ask yourself the question: what kind of writer are you? The kind who survives? Or the kind who gets asphyxiated by the tentacles of woe? 
Chuck Wendig