Finally I stopped being lazy (and, perhaps, blissfully ignorant?) and got out my measuring tape. The body circumference was a full 4" too big!!! I went back to my spreadsheet and found a big error (a typo in my gauge!) which, of course, affected every measurement and made my sweater sized for a small elephant. (Ok, not quite that big, but still far too big for me).
So I reworked all the math, and with a few sniffles, I ripped out three weeks worth of knitting. Then I had a glass of wine. But the bright side of this story is that I made a few more tweaks (including changing the rib pattern), and ended up with a cardigan I absolutely love.
I wanted to create a classic vintage-inspired cardigan that looked chic but was also very comfortable and functional. There have been so many times where I wished I had a small pocket to store my keys while walking my dog, and also wished that my sleeves weren't so tight that I had lumpy bumps from my shirt underneath.