I left a good job as the general manager of a small but very successful business, where the owner was definitely overpaying me and giving me basically full run of the place. I did a good job over several years of working there and increased my pay by almost double from when I first started. Still, I had a boss, and as with any relationship, there will be times when that relationship gets bumpy. My particular boss, despite being a good guy in general, was not good at interacting with subordinates(including me) without insulting them and basically stressing them out with threats of losing their job and/or being docked pay. I had several clients who were in expediting(the business was an auto-repair facility, car dealership, and trucking company housed in one very large building.) So I learned a very small amount about expediting through casual conversations with those clients.
I decided to take the plunge into expediting after a particularly bad argument with the owner of the business I managed, where he basically reneged on a deal, cutting my commission on vehicle sales in half retroactively(so on a vehicle I purchased, repaired, and sold already, I was not going to get paid what was agreed upon.)
I had already been considering and planning to get into the business to lower my general stress level from having to deal with a boss, so I already had a van purchased and all I had to do was upfit it for expediting.
To this day, my old boss will still hire me back if I ever want to stop expediting. Despite leaving after an argument, I did my job well, and left on a good note, offering to help with whatever he needed to facilitate replacing me.
Looking back, there are some things I would have done differently. Lawrence gives good advice here. If I were to do it all over again, I might have went to work for a fleet owner first just to see how it all worked. Also, whatever you think you'll need, money-wise, to get started as an owner-operator, double it. Everything costs money, and to have a truck set up right to be on the road consistenly, you need to have proper equipment and upfitting of the vehicle. I started out with no generator, no inverter, no independent heating/cooling, 2 12v power sockets(1 broken), and a wood floor that I installed with e-track. It's hard to basically live on the road in such a spartan manner, so it encourages you to go home more often, which is a money trap. It costs money to go home. Every time you go, you pay for that gas. And at least with me, the allure to spend "just one more day" at home after spending that money to get there is too strong. It's easy to end up being a part-time expeditor with companies that don't specifically require you to be available a certain number of days per month.(I wouldn't have it any other way, but it's still easy to take too much time off.)
That said, I have no regrets about leaving my old job to get into expediting. The freedom to set my own schedule, take time off when I need it, and just generally be the master of my own destiny is infinitely rewarding in the form of a healthy psyche, even if less rewarding materially.
Just make sure you're financially prepared for the worst, because eventually the worst will happen. You'll pay thousands of dollars to replace engines/transmissions, and you HAVE to have a very healthy cushion as an owner/operator to do that. You can't depend on future earnings in expediting to build that cushion. You need to have it at the start, because what if you have one of these things happen in week 1 of expediting? Things just come out of nowhere on you, and as the master of your own destiny, you have no one but yourself to depend on to take care of things like that. And working for another fleet owner, you really don't make enough money(in my experience) to save up money to become an O/O, so if you have a good job now, you should save up all the money you'll need to become an O/O before you even go to work for a fleet owner.
Others have said it before on here, and it was good advice. Probably 75% of owner operators out there are 1 breakdown away from being an Ex-Expeditor. Don't be one of those guys.
EDIT: Sorry for the wall of text. Guess I got carried away.
