Agent Jessica, of Bookends LLC, has a post here about getting rejected by your own agent. An author apparently sent a manuscript to her* agent, who didn't like it. That's gotta suck. I don't look forward to it, myself.
But I have to say that I totally expect it to happen.
By that I don't mean that I have low self-esteem and that I will inevitably be rejected. (Believe me, I have issues, but low self-esteem? Not one of them.) It's just that, like when I was querying agents and expected to be rejected, I fully expect that someday I will send something to my agent and he'll be like "nah, I don't think so. What else you got?"
I don't know where I got that expectation--whether I picked it up by osmosis from the Internet or it was just something I assumed--but when it happened to a friend of mine, not too long ago, I wasn't at all surprised. Disappointed for him, because, like I said--SUCKS--but not, like, shocked.
I think this kind of rejection is just one more of those things that you have to go through if you want to publish, especially if you want to publish more than one book. The more I contemplate actually doing this--writing, professionally--the more I realize that it's about perseverance. Perseverance just to get the damn thing written in the first place. Perseverance in the revision and polishing. Perseverance in the querying, then the submitting, then the selling. (And, in the meantime, perseverance in the writing of something new while all of the above is happening.)
What do writers do? Writers write.
And what do published writers do? Persevere.
*I'm assuming so I don't have to use the awkward his/her construction.