Disclaimer: I don't own Naruto
Sometimes, Kakashi thinks, Zabuza was right about him. He still remembers those words that were said.
"You're nothing but a cheap copycat!"
He fought many enemies, and they said various things throughout their respective battles, but that one line stung more than he cares to admit.
He thinks it's because he himself believes it to be true, that if he couldn't copy, he would be nothing. He realizes that against any opponent chuunin or higher, at one point, he uses Obito's Sharingan. He then wonders if he is really that weak without the Sharingan.
He wonders if all of his opponents felt the same way as Zabuza, that he was nothing more than a copycat and jutsu thief.
All of the jounin have some way of remembering all of the lives they've taken in their own strange manner.
Asuma remembers by smoking, feeling the smoke go into his lungs, inhaling the crushed dreams and memories of the countless lives that have fallen by his trench knives, honoring the comrades he couldn't protect, the teammates who he doesn't have anymore. One time Kakashi told him that smoking does horrible things to a person's lungs. Asuma just smiled a sad smile and said one line that haunts Kakashi in his dreams.
"I know, and I hope I die from it, because then the deaths of those I killed won't be in vain. They will be satisfied, wherever their souls may rest, that they finally have killed me"
Kurenai remembers with her illusions. For every person that died, another petal on her famous Tree Bind of Death bleeds from pink to the crimson color of a dying shinobi's blood. When she kills another with it, the petals fall from the tree in mourning of a new bloody petal to be added. Last time Kakashi saw her use it on someone else, a large portion of it was red, she'll have to make the tree bigger again soon, he notices offhandedly.
Gai remembers by his training. Every ninja that the large eyebrowed man killed, another ten pounds and five reps to everything were added. Last time Kakashi checked, the man was at ten-thousand pounds, five thousand pushups, pull-ups, and sit-ups, and five thousand laps around the village on his hands. He hopes Lee never finds out this shadowy part of his sensei.
Ebisu remembers by drawing, a habit he picked up trying to find a way to relieve stress from his missions. He remembers his opponents by drawing their faces to a remarkably accurate degree and taping them to the walls of his house. As he is a non-combat shinobi, he kills a lot less, but the pictures cover his room, and he once confessed to Kakashi that sometimes he believes they glare at him during the night.
Genma remembers by almost obsessively writing the names of everyone he killed on the walls of his house. Kakashi knows this from a time when he entered Genma's house so they could drink together when all of the bars were closed from it being 8:30 in the morning. After a few drinks the words on the wall seemed to produce an amount of killing intent. To this day neither is sure it was completely the alcohol. Kakashi finds it amusing that the sake burned the sight of him mask-less out of Genma's memory. Genma doesn't.
He doesn't know Hayate's or Anko's, but he naturally knows his own.
Kakashi remembers in his ninjutsu, or so he tells himself. The truth is that he normally uses only twenty or thirty of the thousands of jutsu he knows, and he can only really remember the copied off of for the four jutsu he stole from Zabuza. He tells himself once more that he remembers his kills in the jutsu he took, but then Zabuza's words ring clearly in his mind.
"You're nothing but a cheap copycat!"
What would be different if it were him that died under that boulder during the war? He had no doubts that Rin would still be alive. Obito would have known not to trust the Sharingan's so called infallible dodges. It was by his idiocy that Rin was hit in the back of the head with a kunai. In fact, if Obito was alive, the Uchiha massacre might not have happened, he reasoned, recalling how Itachi followed his uncle to the point of clinginess.
He made far too many mistakes, and from every mistake another comrade died. Itachi was the only one from his ANBU squad that made it, and look what happened to him!
Far too many mistakes, far too many regrets, and he can't even assure himself that he can remember his comrades or his enemies.
He knows that Obito would remember better, Obito always had better memory. He was the one who remembered to tell Minato-sensei that Kushina's favorite flowers were Momoirobara and she hated Tsubaki for some reason Kakashi never bothered listening to. He wishes he had.
He then saw the time, slipped into his familiar eye-smile, and went to meet with his adorable students to tell them about the chuunin exams…seven hours late.
'I'll tell them that some three foot tall marshmallows attacked the village and I was drafted to help' he thought, pulling out his book of pure awesome.
AN: All done, a drabble on Kakashi and the ways everyone remembers. This is my first story and I hope it's not bad. I didn't think up ways for Hayate and Anko to remember because Anko doesn't strike me as someone who mourns for who she kills and Hayate has less screen time then Tenten.
Momoirobara pink rose
Tsubaki camellia
I made up Kushina's favorite and least favorite flower to show that Obito had good memory, but you most likely already knew that.
Got the Idea while playing through Path of ninja for the eighteenth time from Zabuza when he yells out that line.