When you have less, you don't get as far, that's a sad fact that I wish weren't true. I seriously wish you were correct phillipduran. All of us do. It's just not the case.
I'd say he's partially correct, though he's falling short by applying too simple an answer to a complex equation with a thousand moving parts.
It's a truism that a forward thinking attitude does play a large part in gaining success. Even if you grew up dirt poor and abused, standing up for yourself one day and deciding your sick of it is that first big step towards making something of yourself. It's something anyone can do.
But on that same note, not everyone can afford to fail as gracefully as others. If you come from a rich background, a failure isn't a massive setback. You still have tons of assets and support to fall back upon. It takes a massive amount of failures to reach the point where you're truly hopelessly dead ended. Someone coming from a poor background, where one fateful day could mean the dividing line between the first step towards success and homeless destitution don't have that same luxury. Everyone has their mental breaking point, or financial point of collapse. Failure, quite simply, hurts much worse for the poor.
Plus there's the whole issue of psychology to take into consideration. To put a simple spin on it, most people tend to become what others think of them through positive or negative reinforcement. Now this isn't to say that everyone is fated to become X or Y, but it does play a big part in how people approach life. If you draw a nice picture as a kid, and everyone will talk about your natural talent, and gush over how awesome it is. In turn, you're going to spend more time drawing. You'll likely grow up to be, well not necessarily an artist, but someone who can draw. This is true of people who are told they're worthless trash their entire life. Most people internalize that. Don't even try to better themselves because they think the life they're currently leading is all they deserve.
Though anyone at any time can say screw it, I can better myself no matter what everyone else says, and I'm going to do it, and they just might. But if they fail a couple good times, losing the shirts off their back, they might just go back to thinking that everyone was right all along.
Success is a combination of many things. Hard work. Dedication. Wise planning. People make their own good luck, and that takes effort to do. But people don't necessarily control every circumstance that comes their way, and sometimes people with the right attitude might have the right plan for success, but are passed over due to bad timing or inconvenient circumstances. Some people can pick themselves up after that. Others can't.
In short, it's complicated as hell. It isn't merely that the successful people tried, and the poor people didn't. Not always. It's an ever expanding web of a lot of things that are different for everyone. A lot of it is within your control, and some beyond it, that contribute to a whole.
I think realizing this is one big part of being a successful person, either by personal standards, or societal ones. But at the same time, having a safety net in place to prevent people from falling into a hole they can't climb out of wouldn't hurt. The point of government shouldn't be to perpetually take care of its citizenry, but to always bolster competition and social climbing, and this does occasionally mean taking care of the low end.
The liberal ideal is to leverage society to better enable the individual to improve himself and his position, after all.