Dave, in a way you've asked the same question in two different ways. I'll reply here so that we can get a free flow of success stories on the other thread.
I'd like to share what I've watched happen during the last 30 years I've been in this business full time. Over that time I've watched people at the beginning, the "middle", and at the "end" of their business careers.
A few things I've seen consistently hold people back:
Closed mindedness. This doesn't mean they'll "try anything" (that can make you broke quick), but if you spend all your time saying "that will never work, nothing will.
Lack of focus. This business has so many niches, often its a matter of not staying with any one part before a cleaner dashes off to the next. The cleaners who have the discipline to take one part of the business, and stay with that till they get it right, then go to the next do better than the ones who give up after a month or so and try something else.
Lack of support at home. This seems a bit personal, but I can tell you that a supportive spouse makes a huge difference when sacrifices need to be made to get things started.
Expecting too much, too soon. If you have to always be "eating your seed corn", you can never make it. Many businesses need to be started while the cleaner has a job, or his spouse does. (See above)
Lack of Patience. Few businesses grow fast. I would guess most of the truly successful people here had to live a little bit lean at first. I had a guy get out of the business after three months because he hadn't yet turned a significant profit.
Lack of work ethic. (Ok, I mean laziness). This business is not for the lethargic. If you can't get out of bed, can't work hard, make sales calls, do paperwork at night, do work late at night/early morning, and perhaps hold down a part time job at first, its not for you.
I could go on. Dave, I think this is what you might have wanted. I hope it can help get the thread where you want it to be.
I'm looking forward to seeing the success stories on your other thread.