I'm still in the setup phase of my business (a hydroponics farm/green wall installations) but being able to devote entire days to getting going has been immensely helpful.
I started working the new contract about a month and a half ago. It was hard staying focused at first and I was a little too happy - go - lucky with my newfound freedom (Overwatch). So, while I was getting everything done for my 9-5, I've been moving slowly on the farm. Things have been better these past two weeks and I'm excited to get cranking in a serious way.
I should note that before I had even considered building a business or taking this step, I'd been doing research for the past 4 or so years that started my last semester in undergrad. I'd also done many small scale, non commercial projects for different clients in the evenings/weekends before I made the jump. Like another poster, to me, this is the equivalent to grad school. I could spend a bunch of money on an MBA and learn some things, or I could start this business, learn hands on, and potentially walk away with profit instead of debt.