image courtesy familymwr
It's amazing what people can do once they know it's possible. The SuperHappyDevHouse hackathons occurred because Jeff Lindsay and David Weekly threw a party for hackers, and a dozen people showed up. Now hundreds attend every month. (By the way, SHDH 44 is this Saturday; click here to register)
Every great thing gets started because someone decided to just do it. It's like a standing ovation after a performance. When the first person at the front stands and starts applauding, it gives everyone who wanted to, but was too cautious the permission to express their feelings as well.
Of course, sometimes you end up the only one standing. Not every performance is ovation-worthy; not every crowd us ready to erupt. But that's a small price to pay for the chance to bring something great to the world.