Easy for me -- the first match of the year, Utd in Houston. City fans outnumbered 20-1, sat with rags all around me. They had been in the states for a while; it was our first match of the new season. Lost 2-0 (first goal on an Ederson mistake) and had to listen to them big themselves up. All exhibition, all experiment, but I had to deal them filled with hope un-dented by reality of their shite-ness. This was "their year" they said; we were "overrated." But I KNEW we were better.
Worse, in the 18 City matches in the UK (and a few here) over the last decade-plus I have witnessed live and in person I had never seen City lose nor even draw, ever. I was 17-0-0 til then (I got lucky in 06-08!).