Doc Sigma after a day well-spent with the neighborhood squirrels: "For you, the day I crammed you up my ass was the worst day of your life...But for me, it was Tuesday."
Mokuba's response in Yu-Gi-Oh! The Abridged Series to being kidnapped by Noah. He's so used to kidnappings he has no fear of the situation and insists on Noah feeding him and letting him watch Spongebob. This happened more in the anime, when having Seto involved in an arc pretty much meant Mokuba had to be kidnapped to give him an investment in the outcome.
Played for laughs in The Cosmic Adventures of Doctor Fabulous. Zorg claims that he's battled Doctor Fabulous over the fate of the universe a dozen times. The Doctor retorts that he fights a thousand scumbags like Zorg every week.
Salon's "Interview With My Bully" series has a recurring theme in which the bullies, years later as adults, said they had little or no memory of the things they did that left the authors scarred for life.
Minion:You Monster!!! Two months ago you made me eat my own children! Diamanda Hagan: Oh. An important day for you, but for me it was Tuesday. Minion: And you steal dialogue!
In Worm, when confronted by one of her (many) victims, Doctor Mother admits that she can't remember the codename Cauldron gave her (Garotte), the number they assigned her after they wiped her memories (1616), or the name that she picked for herself after being incarcerated in an asylum after uncontrollably acquiring a three-digit body count (Sveta).
In Cockroaches 28.5, Canary, Imp, and Weaver have this conversation after convincing the Endbringers to work with them:
Canary: This is crazy. Imp: This is a Tuesday for us. Weaver: It's really not. Ignore her.
Not in those exact words, but when Skitter is talking with her lawyer regarding her (impressively long) rap sheet, she starts to have a hard time pinning down which events happened on which days, to the point that she's almost relieved when she can pin down a charge to a specific day.
In a more positive version, Skitter incites a near-riot at her old high school to get away from Dragon and Armsmaster, who cornered her there specifically so she would take hostages so they would be justified in using excessive force. Afterwards, one of the students who helped her tells her they did it because she saved their father's life, and Skitter's only thought is 'I did? When?', showing she actually has lived up to her dream of saving people.
In Bonews: The Fall of Gurts, Xiphias suffers horribly after being microaggressed by Railgun regarding Italian firearms. This is an especially interesting example, because there was a reciprocal incident much earlier in the series wherein Railgun innocently inquired after an improvement to Bulb Infrastructure, and Xiphias casually dismissed him, harming his feelings and eventually resulting in his heroic quest. All in all, the 2013 season was tough on everybody. The 2014 season is off with a bang as these two titans have AGAIN slighted one another, this time regarding ancestry, and are now returning to muster their respective regional armies. How this will end is anybody's guess.
In the Unshaved Mouse blog, which reviews Disney films and features an immortal, black-magic Walt Disney as a recurring character, Uncle Walt has this response upon seeing the latest villain in the Food Fight review.
Walt Disney: Who are you?
Shadowy Figure: Someone who owes you a lifetime of torment. Someone who has suffered at your hands like no other. Someone whose desire for revenge burns like the fire of a thousand white hot suns.
Walt Disney: That could be literally anyone. Care to narrow it down for me?
Unshaved Mouse: P. L. Travers maybe?
Walt Disney: Ooh, good guess! Pamela, is that you?
In Noob, killing Sparadrap's pets made Roxana one of the two people hated by the series' All-Loving Hero. When Sparadrap confronts her about it in Season 4, her reply comes down to "I'm leader of the Player Killer guild, I don't remember every single bullying act I perform," despite the fact that Sparadrap is also in a Mistaken for Badass situation with one of her subordinates. In Season 5, Sparadrap starts attacking her each time he gets the opportunity, which has the side effect of getting a better place in her memory.
A heroic version shows up in one of 4chan's "Humanity, Fuck Yeah!" stories. In the story, a random, everyday human piloting the space equivalent of a tugboat gave his life to stop an alien warship from crashing into one of their own colonies, which would have killed millions of their citizens or more. Years later, humanity is on the losing side of a war with a different alien species when the first aliens show up and mop the floor with humanity's enemies. The aliens then demand to know if their life debt is paid, and are increasingly bewildered that the humans have no idea what they're talking about. In their culture, such a deed is rare and treasured, and is cause to owe an enormous debt that may continue for generations. For humanity, which has been in war going on over a decade filled with soldiers Jumping on a Grenade, random people doing a You Shall Not Pass or performing a Heroic Sacrifice for the sake of strangers, such a thing is just another day. Link◊