Oh you noticed !! It's mostly habit, but 9/10 times I reach for a sweater before a jacket when it gets cold. Dressing for the weather is a matter of progressive layering.shirt -> shirt + sweater -> shirt + sweater + jacket -> shirt + sweater + coat -> shirt + sweater + coat + coat -> shirt + sweater + coat + coat + coat . . . + coat -> Infinite Coat Regress -> it finally gets warm again.