> By hunger I mean the raw chutzpah and energy to do something bold, or commit to going in a brand new direction
I haven't actually noticed a decline in that with age. But what I have noticed is that the more experienced a person is, the sooner they're likely to spot when a new direction is probably a dead end and avoid going that way in the first place. Less experienced people tend to have to actually walk in that direction for a while before realizing it's going nowhere.
Older people typically have more money and connections. If anyone could start a company I guarantee you more young people would start companies.
And not to mention experience. You may want to start a company when you're younger, but it's harder when you don't know what you're doing.