But Bill Gates aside, most 40-somethings aren't yet financially secure enough to give huge chunks of wealth away.

FORBES: A charitable hedge

"Like lots of 20-somethings their days didn't begin until two in the afternoon, " he smiled.

BBC: Michael Mortiz

Kalfayan's parties raise thousands of dollars from 20- and 30-somethings who normally couldn't afford to attend the fancy black-tie fundraisers held by more traditional charities.

FORBES: Magazine Article

"I don't know if I want to be surrounded by 20-somethings, " she says.

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