The generally rule is risky growth assets in youth, guaranteed fix inome assets in old age.

When you're old, you want to buy bonds or annuities. You may buy a rental house with cash. You don't borrow and you don't buy anything where you have to wait for harvest.

When you're young, you take more risk and look at long term growth, and not immediate income. Borrowing money and putting it at risk is common.

Of course the economy is fucked, so investing in youth is not what it was for the boomers.