That's intetesting: Joel Meyerowitz took the same route as you did. He was sent to meet with Robert Frank who was to do some photography for his agency, and ended up so impressed with the fact that photography could be a mobile, active and living thing, that he went straight back to the office and resigned. The rest became a certain kind of photographic history.
Regarding the other thing - dedication: I don't think anyone can ever get anywhere in photography without it. It's a 24/24 business, and that includes the times other folks have weekends and holidays.
I guess that the thing about being or not being married also has a huge input. If you are not, it's easier to do the 24/24 number because it doesn't screw with anybody else's life and day; if you are, you have to be damned lucky and have a woman who isn't going to criticise, moan about irregular income and hours, about models being perhaps a little too friendly (though it means nothing) and seen as competition. I guess we were both very lucky, and once mine began to take an active part on trips, it made the entire shoot far more of a buzz because we got to spend so much more good time together. With the wrong wife it would be a nightmare, and end in business failure or divorce; nobody could live under those sorts of domestic pressures and work well..