To be successful as an entrepreneur there is a requirement to be a bit delusional. Delusional enough to have others doubt you, a few people call you crazy, and get some other crazies passionate enough to believe in you. However, there is a fine line between charming delusion that allows you to overcome fear and leads to a great story, and being oblivious to signals that are right in front of your face.
When it comes to a dream far greater than others can see, a little bit of crazy is a must, but it becomes a problem when you start ignoring the numbers in your business or customers reviews of your product. Keep dreaming, but not at the expense of your business.