Thanks for the comment! You know you're an entrepreneur when you get hit hard cry it out and get back up.
Life is complex and blanket dogma such as "never quit no matter what, screw the haters!" is detrimental. There ARE situations when you SHOULD quit. Recognizing those situations may be hard, but it's still worthwhile to consider quitting.
I don't care what fantasy of glory you're trying to chase, but for the love of god please be pragmatic about it and consider the entirety of the situation before making a decision that can impact your life in a big way, for better or for worse.
Sunk costs can be a bankrupting, nation destroying, and species extincting level cognitive error. Sometimes it is best to quit.
Here's a podcast that goes into more detail:
http://freakonomics.com/2014/05/29/the-upside-of-quitting-a-...
The takeaway is that the quicker you quit the faster you can get on to something you can win at.
However, the message of "Quitting is Lying to Yourself" is that if you have the spirit of an entrepreneur, telling yourself that you'll never do it again is lying to yourself because you know you will find a passion and feel the desire and need to build something new.