Sometimes experts are fallible:

In 1903 the head of the patent office wanted to close the department citing that every possible thing of significance that could be invented by man, had been, That was a few months before the Wright brothers successfully got the first powered aircraft off the ground.

In the late seventies, budding entreperneur Steve Jobs showed off a prototype of a compact personal computer to the board of directors at IBM. The board declined his offer to jointly produce the device, citing that people would have no use for a such a machine in their homes. A few years later Steve forged ahead and that prototype, became the first Apple Computer, the rest is history.

Subsequently, in the late eighties, many experts believed that setting up computers in a network would generate no real use outside the scientific and military communities and that there was no commercial potential for something being called the "internet".

A few years ago John Stossel had a group of high paid wallstreet pros pick some stocks. John then had his staff pick an equal number of stocks by putting them on a bulletain board and throwing darts at them. Over the course of a month, the randomly picked stocks yielded higher average returns.

In the 60's renowned economics professor Kenneth Galbraith asserted that the big three's( GM, Ford and Chrysler) dominance of the auto industry was complete and that the fledgling Japanese carmakers, Toyota, Honda, and Datsun( AKA Nissan) would never be competative in the US. Toyota is now at parity with GM in sales. The Honda Accord and the Toyota Camry have been the best selling family class cars for over 10 years.

Several years ago a business student, as part of his last term paper proposed a high speed mail delivery service. The professor gave the paper a C citing that though the idea was very creative that it could never work. The student dropped out of school and decided to pursue his idea. That idea, became: Federal Express.

In the 1960s experts became convinced that India, within two generations was doomed to massive poverty and starvation. Currently India has the largest middle class of any country in the world and the second fastest growing economy.