I have a friend who has wanted to start a startup for years. Every time he comes up with an idea, he subsequently talks himself down: the market isn't big enough, the timing isn't right, he can't find a cofounder. The reasons are always different, and are always logical.
This is a loser's attitude, and unfortunately it is shared by millions. It is why our risk-adverse society systematically over-rewards those willing to take perceived risks. When you look for reasons not to do something, you will always find them.
I have another friend who came to the Bay Area with the dream of starting a startup. He had no college, no programming ability and no connections when he got here. He got a job serving ice cream, moved on to join a startup, then started his own company after two years. The company is now doing 2 million in annual revenue a year and a half later.
When you approach a challenge with the foundational belief that you can do it, you have a much different mindset than when you approach it with the idea that it is impossible. In the former case you almost always figure out a way, in the latter case you almost never do.
Those with a winning attitude get started and figure out how to get things done. Those with a losing attitude worry about failure, and never get started.