Rejection is a major part of being a writer. Not just for beginning writers, and not just for the less talented. Rejection is so common that it's very nearly a stock part of the story of any wildly successful book or writer to mention how many places passed on the book or didn't sign the writer.
Generally, I think this is fine. I want to live in a world with a wide diversity of literary tastes. I want to place my work in the markets that are most enthusiastic about it. When I get to the point of having an agent and a publisher, I want those people to be as passionate about my project as I am.
But there are different kinds of rejections. And that's where the crazy begins. Because when being turned down is a major part of your career, you learn coping skills. Rejection letters become chemistry experiments: The Distillation of Hope from Despair.
The basic form rejection. There's not much you can do to parse those, although I am sure there are writers out there who try. "Best of luck in my future endeavors. Hmm. Does that mean that he thinks I need luck? Does she want me to have future endeavors?" "The promised response time was 80 days. It took 79 to reject this. Maybe they came really close to taking it?"
The rejection with feedback. A good rejection! My story made it out of the slush pile, and into the hands of someone on the masthead! But wait - what do you mean, you just weren't intrigued by my sparkly zombies? The sparkly zombie was the heart of the story - a comment on the gilded decay of today's society.
The market-fail rejection. As is, "this story was very well done, but too [fill in the blank] for us." (Still a good rejection, because hey! feedback from an actual person.) Note to self: Do not send your lusty pirate story to a market that does not like stories about lusty pirates. Even if your pirates were the lustiest ever, that market will not buy your story. Arrr.
The rewrite request. Excellent! Not a rejection! (yet.) Now, I just need to turn these lusty pirates into sparkly zombies.