I've had a few bad ones, most of them when I first started playing. I had one goof that couldn't really be considered a goof, 'cause the AI caused it, but I'll post it nonetheless. I was playing as the USSR and I was gearing up for war like mad, so I could invade the Germans. I had couped Canada and installed a Stalinist government, and allied them with me (my plan was to invade Germany and afterwards the US). I forgot that Canada always declares war on Germany (around early 1940) regardless of who they're allied with, and before I had my troops ready (not to mention that a large part that I had ready was in the East, conquering Afghanistan, Persia and some of the Chinese warlords). Needless to say, Nazi forces were overwhelming and before I knew it the Germans had already taken the majority of the USSR and I couldn't fight back for shit. Just before I gave up I had one last look at Canada, and saw it was nice and quiet, sending me one tactical bomber as reinforcement.... 