My most shameful moment that I can recall currently was roughly last summer.

My alliance got into a war with a rivaling top alliance in the state, supported by the #1 alliance on the server, amongst a few others. I wiped out or assisted in wiping out some 40-50 red flags within 20 miles of my little corner of the world, most if not all of the enemy targets with more prestige than me, earning me the nicknames "Bloody Princess" or "General of the Silver Faerie Army" in my alliance. It was a prideful and glorious time...

...until I got my entire force wiped out attacking the city of a 2+ month inactive ex-ally with only 1/10th my prestige.

I hated myself for a while after that.