I have put manuscripts, full-out novels, "under the bed." There are multitudes of reasons why--but it mostly boils down to they just weren't good enough.
Advice often quoted is that you must "kill your children" in order to be a better writer. This advice applies to a perfect turn of phrase that doesn't seem to fit, it means cutting scenes that are spectacular but don't-quite-work in the scheme of things, and maybe it means that the whole novel you're working on has to be scrapped.
But, after a conversation with Shane, I've come to realize that putting a whole novel under the bed is not "killing your children."
It's accepting your children for who they are.
We all want our children to grow up to be doctors, lawyers, professional chefs, etc. (Okay, maybe not lawyers.) However, no matter how much we help them with their homework, show them how to groom themselves, or give them all kinds of experiences that we never had as a children, they grow up to be themselves.
We guide them, but sometimes they're gonna live at home until they're 34, or work at McDonald's for the rest of their lives, or, heaven forbid, become lawyers (but the sleazy kind, ya know?). These are the novels that are under the bed. As a parent, you still love them, but you know, deep down in your gut, that they're not gonna be a doctor. So, you let them do their thing. Accept that your expectations may have been too high for them. But don't feel bad because they are what they are.
So, if you've got a book that you're working on, and you love it, but it's not working...Do Not Beat Yourself Up. You did the best you could. This kid just didn't turn out. It's got quirks that can't be overcome. You can still love it. But don't try to send it to med school.
You've got other kids.