"Why don't I remember her?"
Because of me, he wanted to tell his brother. Because I never told you.
He had wanted to, ever since he realized that Sherlock had forgotten. Eurus was erased, and Victor Trevor was turned into Redbeard the dog. But Sherlock... Sherlock was finally living again. Talking, eating, whining, and pestering Mycroft. True, he wasn't the same. There was hardness in his eyes and coldness in his voice that hadn't been there before. But at least he was alive. Responsive. And Mycroft would never wish him to go back to the state he was in before, a hollow shell with empty eyes. So he didn't tell him.
Sherlock was nine when he discovered his old pirate regalia in the attic. He looked at I with mild interest, and then turned away, going back to he squirrel carcass he had smuggled in. Mycroft had seen him, and decided to try. "Do you remember Redbeard, Sherlock?" Sherlock looked at him, bemused. "Our old dog? What's he got to do with anything?" He became engrossed in dissecting the carcass once more. Mycroft saw him, biting his lower lip in concentration. He looked content, and Mycroft didn't have the heart to upset him. So he didn't tell him.
Sherlock was ten, and he was having trouble at school. The usual petty squabbles and ordinary taunting had escalated into open warfare. Sherlock had become vicious in his verbal dissections, aimed at schoolmates and school staff alike. The kids began responding with physical violence, and Sherlock retaliated with destruction of their property and even more hurtful verbal assaults. His teachers were accusing him of turning the school into a battlefield.
Mycroft, the ever responsible older brother, took him aside for a lecture. All he got in return for his conscientious efforts was snark. Sherlock seemed unable to comprehend the connection between his behavior and the results. Or, more likely, he just didn't care. Perhaps it was time, Mycroft mused. Perhaps he should remember what he once knew, how to have relationships with other humans, and how to keep it. "Sherlock, have you ever heard of the East Wind?" he probed.
His little brother looked at him blankly. "It's an old Greek legend." Mycroft was treading carefully. "Eurus, god of the East Wind, will come and blow away everything unworthy in her path."
Sherlock looked at him, in confusion mixed with burgeoning insolence. "What does that have to do with me? Are we going to have Ghost Night? Make a campfire and stuff ourselves with marshmallows? Oh, I forget, you already ate all of them."
"No, Sherlock. That's not what I meant." Mycroft was exasperated. "If the East Wind comes in our direction, it won't have to look too hard to find someone unworthy to blow away. You should watch your back, brother mine."
Sherlock stuck out his tongue and then moodily stomped off. He doesn't have a clue, Mycroft reflected. If I tell him now, will he get worse? Will he fall apart again? I must attempt this again at a later point, and see how he reacts. In the end, Mycroft still didn't tell him.
Sherlock was fourteen, and experimenting with drugs. It started with cannabis, and proceeded to heroin. Mycroft was called home from Uni by his frantic parents. "Why, Sherlock? Why must you destroy yourself like this?" he asked his brother in disappointment.
"That is really none of your concern. I could ask you why you don't lay off the pudding and lose the fifteen pounds you gained, but I won't. Stay out of my business and I'll stay out of yours," Sherlock sneered.
Mycroft's disappointment bled into rage. "Don't you see how you're hurting Mummy? Don't you see how you're destroying the family?"
"You never understand!" Sherlock burst out in rage. "My brain is running, running all the time, all the thoughts spinning around and around, and I need it to STOP! You don't care! You're just an idiot like everyone else!"
Mycroft stood silently in front of his brother, his head bowed. He felt adrift, lost in the raging sea that was his brother's psyche. "I do understand, Sherlock, believe me, I do. I hope you can find a better method of coping, because you're going down a dangerous path. Do you remember the East Wind, brother? It's coming for you, Sherlock, and you have placed yourself in its path."
"I'm grateful for the warning. I'll just shove you in front of me, and problem solved. Is there anything else?'
Mycroft pierced his brother with a stare. "Do you remember Redbeard, Sherlock?"
"Have you hit your head lately? I'm not a child anymore, Mycroft."
He doesn't remember, but the demons still haunt him. Will bringing them up help to exorcise them? Or will they destroy his psyche completely? Can I risk it when he's in such a vulnerable stage? Mycroft pondered those questions, but still, he didn't tell him.
Sherlock continued taking drugs sporadically at fifteen, and sixteen. At age eighteen, he was officially an addict. When he was clean, Mycroft was afraid to drive him back. When he was high, Mycroft was afraid to drive him further. For many years, Sherlock was a pendulum swinging back and forth between a functioning member of the human race and a junkie willing to do anything for his next high. Not once did Mycroft tell him.
How Sherlock Holmes had managed to get a chemist's degree in between his drug sprees was inexplicable to Mycroft. He then began hanging around crime scenes for stimulation, and pestering the detectives. At age thirty, DI Lestrade took the volatile young man under his wing and turned him into the world's first consultant detective. Mycroft and the DI turned into a team, using the stick and carrot method to get Sherlock off his drugs.
The carrot, of course, was entrance to a crime scene. The stick was denial of such. Sherlock still had relapses, but was clean for long periods of time. Mycroft watched him working through his CCTV's, and felt his icy heart melt somewhat in relief. And was that a tiny flicker of pride? But never once did he tell him.
John's entrance was at once a shock, an enigma, and a gift. Mycroft watched, and hoped, and blessed the good doctor in his heart. Sherlock was turning into a man, and perhaps he never would have to tell him.
But there were issues. Danger nights. Moriarty, and faked suicide. Sherlock returning, and being rejected by John. John leaving Sherlock to marry a woman. All Mycroft could do was ask. "Do you remember Redbeard?" And remind him. "Remember the East Wind, brother mine." But never could he bring himself to tell him.
Now he was sitting in the client's chair. Being interrogated. Being put on trial.
"You're going to tell the truth, Mycroft, pure and simple."
Is it ever?
"Why don't I remember her?"
Because, brother mine, I never told you. But now I will.