Entrepreneurs, check your egos at the door.

A man is like a fraction whose numerator is what he is and whose denominator is what he thinks of himself. The larger the denominator, the smaller the fraction.   
                                                                                                                Leo Tolstoy

One of the most dangerous consequences of self-importance in an entrepreneur is inappropriate confidence in hunches about Market behavior.  Watch carefully for, in particular, the appearance of phrases such as "they just don't get it," or "you'd have to be nuts not to buy this."

The Market is, in fact, always right, as I have pointed here many times before.  It may not always be wise.  After all, somebody did sell a bucket load of pet rocks.  And it may not always be rational.  People do buy military off-road transport vehicles to commute to work in crowded cities.  But it is, nevertheless, always RIGHT.  It will do as it pleases, regardless of your opinion.

And Modesty is always in vogue.  Self-confidence is good.  Self-importance is bad.  Unfortunately, the boundary between them is very fuzzy.