Mike Salguero knew he wanted to be an entrepreneur from the beginning. He got his start as a paperboy and worked many jobs along the way, but found he wasn't even really working for himself his first time as a founder. Three days after his first startup folded in 2015, Salguero started ButcherBox. It's made him a millionaire hundreds of times over, he has no intention to sell, and his biggest advice is counterintuitive: don't raise outside funding.