Funny. I just did. Well, technically I asked my wife, but she answered, "Iohno." Like, 'I don't know' with the least possible effort.
What I asked was, "What's it like for people who don't get told they aren't good enough every single day?" This was in reference to a rejection I just received.
Don't worry. I'm not down about it. In fact I said the word rejection out loud like I was Adam Sandler doing Cajun Man on Weekend Update.
Seriously, though. You fuckers! Most of you go through every day without being told you're a dung heap, and the only doubt you face is your own. Your insecurities come from the inside, your fears of things not working out are manufactured by your own guts. I don't have to live that way. I can get told to fuck off at almost any moment. I'm constantly reminded that what I do best isn't good enough. Imagine what that would be like at your job? If the principal took you aside, once every couple of days and said, "Listen, I can see what you're trying to do with those kids, but I just don't think I can endorse it. I'm not sure they'll learn this way. I can't see them being excited about your teaching style. It's possible you shouldn't be a teacher at all. But don't feel bad. Teaching is a tough business. This is just one principal's opinion. Keep trying. Maybe some kid will learn something from you at some point. Until then, you're a shit meatball."
Short Answer: A form rejection (meaning the non-personalized fuck off letter an agent or publisher sends out to everyone who queries them) can say many things, very few of them hurtful, but once in a while, it will say something like, "I just couldn't get excited enough about this project" or something, and those sting a little bit. Not as bad as "You're a festering garbage pile and your life is meaningless, get a real job, you fat hippy!" but close.
Note: In truth, rejections are almost always polite, and sometimes even encouraging. The worst rejection I ever got was a magazine that got excited about the first ten pages of a story and asked for the whole thing. Then, later, they rejected the story with a couple of paragraphs of scathing critique where they outlined that I had totally ruined my own premise. That was a shitty one.