Birthdays are important to Stiles. Scott's birthday is October 6th. Lydia's is August 12th. Stiles even knows that Jackson's birthday is June 15th. His dad's birthday is May 27th and his mom's birthday is...no, was...
Stiles can remember her last birthday party.
Stiles could now calculate in retrospect that it was her 33rd birthday, but at the time, all he knew was that she was 'old' because she was a grown-up far bigger than him. Funny how after that day, he kept on being told how young she was.
Mom had always loved parties and was particularly skilled at throwing them. This one was no different and their backyard was buzzing with an underlying hum of happiness and cheer. It was all just a bunch of grown-ups, holding tumblers that they told him were full of juice, but really brimming with what he knew to be alcohol (He was smart for a fourth grader, thank you very much – he knew what alcohol was). There really weren't many other kids at this party, but the other kids who were there were playing some game on the other side of the yard. Stiles didn't mind. He was used to playing by himself, and he was good at it. Stiles ran around the backyard and when he promptly got bored of that, he grabbed the assortment of sports equipment from the garage and proceeded to start making a fort with the baseball bats and lacrosse sticks. Some of the stuff had been handed down from Mom and some of the stuff had been bought by Dad with the fledgling hope that Stiles would inherit a smidgen of athletic talent from his mother (Mom had been a varsity athlete, but Dad...not so much). Stiles got too quickly bored with the rules of serious sports, though.
It turns out that he quickly got bored with the fort, too. So Stiles clambered up a tree and then sat and watched. He saw Dad with his arm wrapped around Mom's waist, gripping a Coke in his hand. Mom didn't like the taste of alcohol and never drank, and this rubbed off on Dad. As far as Stiles knew, Dad did like alcohol, but he would always have just one alcoholic drink and then only have Coke or water afterwards. Mom would've let Dad drink more if he had asked, but Dad never asked. Mom just had that kind of power.
Stiles saw people go up to his parents, one after the other, handing them envelope after envelope. Stiles could just barely make out the explanations for each one - "Here's a little gift certificate to the Beacon Hills Steakhouse," "Here's a small gift certificate for that burger joint you two like so much," and "Here's a gift certificate to the new pizza place in town." Dad sucked at feigning surprise, but Mom always smoothly thanked the gift-bearer and made some response that made her seem genuinely excited about the gift certificate. Mom was always really good at talking to people – sometimes she talked a little too much, but for the most part, it was what helped her make so many friends. With these gift certificates, though, Stiles knew she was definitely faking it.
Stiles realized with horror that he hadn't gotten his mom a present. Granted, his parents didn't really give him much of an allowance, but still. He wanted to give her something that would actually surprise her. He obviously couldn't get her anything material at this exact moment, but his brain sped along and devised a plan.
Dad was called over to the grill and Stiles saw his chance. Stiles heard himself roar "HAAAAAAPPY BIRRRRRRTHDAYYYYY!" as if in slow motion while he flew out of the tree. He accidentally ended up kinda kicking his mom in the sides as he landed in the perfect piggyback position on his mom's back. The two of them held that position for just a second. After that second, Mom crumpled down but instinctively rolled over a little in order to protect Stiles from hitting the ground too hard. His mom seemed to have the wind knocked out of her and she seemed to be having a little trouble breathing, but Stiles attributed that to the fact that she was also laughing really hard.
Mom wiggled over on the ground and hugged Stiles, both of them still lying down in the grass. "This is fun," she said simply.
Later that night, after Mom turned off the light so that she didn't have to see the dishes piled high in the sink and the balls of synthetic tablecloths in the yard, she bumped into the side of the kitchen table. "Ow," Stiles heard. Then, in a tone of casual surprise, "Stiles, I think you somehow bruised me when you jumped on me today."
It was those bruises that made Mom go into the hospital. Stiles looked up all the big words the doctors used and so he knew that Mom had no chromosomal abnormalities, no antecedent hematologic disorders. Basically, his mom had no reason to have this thing, this acute myeloid leukemia, except for the bruises he had made.
Stiles looked up everything he could so that he could figure out a way to fix what he had done. But everything happened so fast – almost as soon as the doctors diagnosed her, they put her on Induction Chemotherapy and within a month, she was in CR1 – remission, which Stiles knew didn't mean a cure so he couldn't stop researching. Then there was Consolidation Chemo and then Transplant and then Maintenance and then – the worst – Relapse.
Maybe he should have done his school reports on cancer. He definitely had learned all about it.
The Stilinskis had one year of relatively normal birthdays, while Mom was on Maintenance Chemo. Mom wanted Stiles to have at least one more, so even though the doctors advised her to have another transplant as soon as she achieved another remission, Mom insisted that they wait. She waited because of Stiles.
Stiles would have rather seen his Mom have one more birthday.
Mom had an especially rough time with this transplant – she got some virus infection and something called mucositis and on top of that, graft-versus-host disease. The way Stiles understood it, this GVHD thing was because the chemo and all that other stuff didn't wipe out Mom's body enough and so her body was fighting the infused cells. Stiles knew that his mom was a fighter, but he found himself wishing on the stars, the full moon, on every possible mystical thing that his Mom would just stop fighting.
Thankfully, Mom somehow made it through, and although she was worn down to practically nothing, she still insisted on planning a birthday party for Dad. They convinced her to whittle down the celebration to just a family affair, but still, it was the greatest Wild-West-themed birthday party Stiles had ever been to (Dad had just been offered the job as Sheriff and the idea of Sheriff Stilinski with a backdrop of the Great American Frontier tickled Mom very much).
Stiles began to think that he could plan ahead to his mom's next birthday. She had mentioned wistfully once that she wished she could practice lacrosse with him. Stiles had immediately responded that she was going to get better soon, he knew it. Mom just laughed in the way that she did and said that it wasn't that she didn't think she'd get better – it was just that all the sticks they had at home weren't the right size for her. Stiles knew at that moment what her next birthday party's theme should be.
But all his planning suddenly came to a halt when Mom went in for her 100-Day-Post-Transplant visit and came out with the word 'relapse' again. She had felt fine, how was it possible that she was relapsing? But no, her blood was betraying her and was full of too many blasts (Stiles had to look those up, too, and he thought it was unfair that something with such a cool name could be so terrible). The doctors hadn't even settled on a therapy plan when Mom went into the hospital with a headache and Stiles added a new phrase to his expanding vocabulary – subdural hematoma.
Now Mom was hurting in the brain as well as in the blood. Dad wouldn't let Stiles miss school, so he was stuck there every day. How was he expected to pay attention in school when his mom was throwing up and slowing down in breathing and - Stiles didn't even allow himself to say it in his head - but how could he stay put in his seat when Mom was dying?
And when Stiles went to the hospital right after school that one day, she wasn't responding to his voice. She wasn't responding to anyone's voice. And she wasn't really breathing; she needed a tube. And Stiles had never been afraid of seeing blood, but now Stiles was afraid of what was happening in blood, because he looked up 'DIC' and now the blood running through Mom's body wasn't just full of blasts but was also clotting inside her blood vessels.
Then Dad sat him down and they decided; they decided without it even feeling like a choice had been made.
Her birthday came and Stiles ran his fingers over the perfectly-sized lacrosse stick he had gotten for her. Birthdays are important to Stiles – because they were important to Mom.