lhankins
I think the best designs and ideas come about through a process which is not unlike evolution. You might start with something good in isolation, but being subjected to many differing viewpoints and perspectives will challenge your idea, and force you to flesh it out in ways you may never have done on your own.
In keeping with the evolution analogy, this type of force causes your original concept to mutate into something which is (often) superior.
I started my current company when I was 26. I think back to that time (1999) and I didn't blink an eye when it came to the risk. I jumped in quickly, without worrying about it.
Now its 8 years later. I have a wife, a kid, a house payment, etc. I would definitely think a lot harder about making that type of move now. Obviously, my salary is higher (which is one aspect of it), but the big reason is that my obligations are much higher. If I miscalculated now, my family would suffer greatly.
So in general - I'd say younger people with less obligations and responsibilities, are more able to take that type of risk.