The list makes no sense
Of ocurse it's 'cinematic', and it also acts as a spoiler (why spoil the ending by showing Cottonmouth is already 'taken care of' so early in the movie?), but think about how much sense it actually makes.
People make lists so they don't forget important things. Oh, I need to buy shampoo and Q-tips, I better make a list so I won't forget in the hypnotic glow of the overly bright neon lights in the supermarket with the elevator music and ads blaring into my ears - that's understandable.
But this supernatural being (how else can you explain her taking so many hits, even relatively deep-looking flesh cuts without her getting an infection or any problems whatsoever in her functionality although she never gets any medical treatment for the things that would've definitely killed pretty much anyone, especially in the long run), being SUPER passionate about revenge and killing the people that SHOT HER IN THE HEAD and she survived (The professional ASSASSIN GROUP does not MAKE SURE the victim is dead.. no checking of pulse afterwards or anything?)..
Ok, I always get too many points in my head when I try to explain one simple point, because everything is connected - for example, the 'anime' scene shows 'Beatrix Kiddo' being WAY too passive when they're punching her, considering what she does in the 'live action' scenes in this movie - she could've at least blocked one punch, even if she is pregnant? Couldn't she at least have punched back a little bit? Just LOOK how PASSIVELY she takes every punch, and how weak and non-combative she is!
Let me start again with the point about the list - this supernatural superwoman with super fighting skills, ENORMOUS passion for revenge, NEEDS TO MAKE A LIST so she won't forget to kill someone?
'Oh, Cottonmouth! I KNEW I forgot to kill someone, damn!'
Really?
Also, even if she does forget to kill someone, so what? She will remember that someone sooner or later, I am sure. She is so passionate about it, she's HELL-BENT on revenge, she has been traumatized by the group and the 'event' so much that she would have NO problem at all recalling the event in detail and thus remembering every single face and individual easily.
Also also, she was IN THE GANG, she knows everyone pretty intimately, how could she ever forget ANY of the extremely memorable characters? I mean, those characters are even memorable to us, the audience, how much MORE so it would be for her?
And yet he needs a list, with SUPER BIG LETTERS, so everyone around her in the airplane can see, and she also needs to CROSS OUT names, so she will ALSO remember the people she haws killed.
What? Killing someone isn't big enough an event to REMEMBER WITHOUT A LIST?!
I mean, there are only a handful of people, it's not like she has to remember 500 individuals she has never met, she needs to remember a FEW people she has WORKED WITH FOR YEARS and knows intimately, all of whom betrayed her and punched her down and then shot her in the head.
How would, how COULD she ever forget ANY of them?
DOES SHE REALLY NEED THAT DAMN LIST?!
No. The list doesn't make ANY sense, except to serve the audience and to spoil the ending. I hate when movies do things purely for audience's sake and discard believability and making sense in the character's mind or the movie universe's perspective.
Just like about 800 things about these movies, the list makes absolutely no sense.
To add, why would she need a list of those people she knows so well and has worked with for a long time, but NOT a reminder note/list/something about Hattori Hanzō, that she has never even met? So meeting some stranger in Okinawa, a place she has presumably never been to before - THAT she can easily remember without a list.
Killing a few people she knows very well she CAN'T remember without a list..?
The list makes no sense.