Choosing your generation?

[Hintergrund]

If it works at all, only with generations without a sharp border. Like with between Xers and Millies. Earlier in the 20th century, it was obvious: The Lost were old enough to fight in WW1; the G.I. were too young for WW1, but old enough for WW2; the Silent were too young for WW2, but too old for Vietnam; and the Boomers, you know.