We've been doing this "Lessons Learned" series for a year, and one lesson that entrepreneurs mention often is the one about staying stealth vs. being open. Many entrepreneurs realize that keeping an idea to themselves actually hurts them more than it protects them. "Every new entrepreneur fears that they have such a great idea, and if they tell somebody than that person is highly likely going to take it and launch it in a weekend," said Nigel Eccles, CEO and founder of Hubdub. Looking back to the 16-hour days when he and his team launched Hubdub made him realize that it takes a lot of work just to get a project off the ground. What's more, just because an idea is shared doesn't mean anyone even gets it, Nigel said. 

"You have to ram the idea down people's throats before they say, 'Yeah it might work,'" he added.

The other mistake that entrepreneurs make is building businesses that are too big to start. Based on his experience at a startup back in 2000, he's a bit tainted. "It scarred me a bit from spending a lot of money, and hiring lots of people."