Then go read venture capitalist Ben Horowitz's post on "Can-do versus Can't-do" cultures.
The post is all about ignoring skeptics and plowing ahead with your ideas, even if they seem outlandish to some.
In the post, Horowitz has the best explanation of what a technology startup represents:
The word technology means "a better way of doing things." This is easy to say, but extremely difficult to do. Making a better way of storing information, a better currency, or a better way of making friends means improving on thousands of years of human experience and is therefore extraordinarily difficult.
At some level, it would seem logically impossible that anybody could ever improve anything. I mean, if nobody from Bible days until 2014 has thought of it, what makes you think you are so smart? From a psychological standpoint, in order to achieve a great breakthrough, you must be able to suspend disbelief indefinitely. The technology startup world is where brilliant people come to imagine the impossible.