I just did.
A couple of weeks ago, I tweeted:

f***ing hard telling clients maybe their “baby is ugly.” #lsmSF#leanstartupMI#EntrepreneurDownDays

The pause that followed was a deep void.  It was emotional.
During the next week of reflection, a non-early adopter, but loyal user of the product called the founder to  announce that he would not after all, pay for the product. Not at the proposed price, not at the price they had argued for, not at any price.
So he fired himself as Founder and CEO of his company.  And then he fired me.  (“I no longer need your services.  But in the future…”)
We talked briefly about his future, including possible pivots and leaps, but essentially, the gig was up.  I admire his self-awareness and the honesty with which he evaluated his situation.
Can you do that?
Yes, it’s difficult to know when to kill your idea.  Yes, you should be knocking down walls to work.  But the market is the final arbiter, not your hustle.
There’s a whole slice of our society based on non-transparency, on not being totally truthful. It’s necessary for polite society.  You don’t always need to hear your haircut sucks or you look fat in that outfit.  But this is a problem, too, when you really need to hear the straight dope.  As a startup founder, you need to surround yourself with people who are willing to speak the truth.
You need to talk to investors who won’t grinfuck you, e.g., those who makes intros to a bunch of other investors, instead of telling you why he thinks you’re not fundable. You need advisors like Dan Martell, who challenge whether you got the stuff, or Patrick Vlaskovits, who will kick your ass because you’re spending more time documenting your business canvas then actually outside the building testing your business model.  Truth-telling is why I admire Eric Ries, who is willing to challenge the most fundamental media myths surrounding startups and “visionaries.”
Gravity’s Zipper
You will be exposed.  If your idea isn’t what you’ve built it up to be in your mind, it will eventually fail.  Believe in  yourself, be skeptical of your idea.  Surround yourself with truth tellers.