Autumnal start, drinking, poetry, Internety stuff

Elizabeth asked, in response to Ask Roger Anything (and YOU still can):

Why do they call the Autumnal Equinox the beginning of Fall when it is already Fall? Likewise the Winter Solstice isn’t the beginning of winter but well along into winter?

Why do “they” say anything? Why do they still use foot/pound? From the Wikipedia: “Some cultures regard the autumnal equinox as mid-autumn, others with a longer lag treat it as the start of autumn. Meteorologists (and most of the temperate countries in the southern hemisphere) use a definition based on months, with autumn being September, October and November in the northern hemisphere, and March, April and May in the southern hemisphere.

“In North America, autumn is usually considered to start with the September equinox. In traditional East Asian solar term, autumn starts on or around 8 August and ends on about 7 November.”

The answer, therefore, is