Acclimating

When I first arrived here in August, 80F was the new 100F.  Then 60 became the new 80, and 40 the new 60, and suddenly 20 is the new 40.  My first inkling that I have become acclimated came a few nights ago as I walked from the train to the grocery store to my home, all without a coat on, but my suspicions were confirmed just now when I felt genuinely surprised by the fact that we're just now hitting 20 today and I didn't shiver once walking home from the train.