I know the words "Everyone Else liked it" have power in your mind. They give you comfort when confronted with your first negative review, and soothe the sting of criticism.
But they're not magic. They don't make the review go away, nor do they invalidate it. I know you want to think they do, but they don't. Truth and reality are not decided by popular vote.
Also, let's consider for a moment who, exactly, makes up Everyone Else. I hear those capitals when you say it, and I'm using them for your benefit, but Everyone Else isn't really the vast number of people you're implying it is. It's not Everyone Else on the planet. It's not even, really, Everyone Else who read the book. Not everyone who reads a book will review it. Bizarrely, people who hate it are among the first who will refrain. (This is bizarre to me because you'd think that they'd want to warn other readers.) Seeing as the same sort of author who will trot out the "Everyone Else liked it" argument are also the first ones to say readers shouldn't write negative reviews because they're "mean", this is quite a handy little piece of self-serving rhetoric. If readers aren't allowed to say they don't like something, then of course your reviews will be overwhelmingly positive. That doesn't mean Everyone Else liked it; it means you've managed to stack the deck in your favor.
Most likely, Everyone Else consists of your friends and family, people who feel compelled to support you more out of love than because you actually have talent. They have on the rose colored glasses, and/or they don't want to say anything negative for fear of hurting your feelings. Everyone Else also probably includes a few carefully selected bloggers--the kind who are more interested in cultivating friendships with "authors" than in critiquing books, or the kind who are known for going easy on first-time authors, or for having a soft-spot for your kind of fiction. The book blogger equivalent of the "easy A".
In short: Everyone Else is the easiest audience you'll ever have, and you know it. It's why that first negative review stings so much.
Please note: I'm not saying this is the case for all of you. I'm saying this is the case for the kind of author who would have a screaming fit in public because of their first negative review. The kind of author who would give up on writing because they didn't sell a million copies first crack out of the box.
And you know what? It's okay if you tell yourself that Everyone Else liked it. If that's what you need to keep your cool and not make a scene, then please: tell yourself often.
What's not okay is for you to say this to your naysayers. Because then you've crossed a line into unprofessional behavior. You're no longer trying to bolster your self-confidence, you're trying to silence your critics. To discredit them. To pressure them into recanting. And on the basis that a very select group of people liked your book.
That's not how opinions work.
With a large number of ratings (i.e. far more than the number of friends you have), it's possible to have a consensus of opinion, but even then, it's not accurate to say the minority view is wrong. There could be more factual basis for the minority opinion than the majority one. The only thing that can truly be said, is that it appears that more people liked it than didn't--and if you're the author in that situation, then you can be happy.
Which is all the more reason not to comment when someone disagrees. You've won the popularity contest. Be magnanimous in your victory.
But please remember that this doesn't make your supporters "right" and your critics "wrong". It just means you've been "lucky".