I recently sent off a submission for a novel to an agent. Because I've published non-fiction for the last fifteen years I had to go through all the steps, again. And, when I pressed "send" to wing off the first ten pages, I felt an unexpected surge of doubt, like I was sending a child off to camp, or to a major recital in front of a crowd.
That took me by surprise. After all, the worst that can happen is a rejection. But.... how hard it is, sometimes, to think of that rejection!