Sorry, if this has some mistakes or doesn't make sense, it was an idea that just popped into my head.
After the war, Hermione developed an extremely rare illness referred to as PTYA. Post Traumatic Yearly Amnesia.
Hermione had suffered a lot over the years and have struggled to come out on top. She nearly did, she was so close. After losing many of her friends in the war, coping with the effects of torture and dealing with the fact that her parents would never remember her after the reversal spell failed, she had finally crumbled. The war had left in a war induced illness that every year, made her forget most things that had occurred. In a way, it seemed her brain was protecting her from all of the hurtful memories that had once intoxicated her mind. On the first year, she had forgotten everything except the people she had been around constantly. She had no memory of the friends that had died, the parents she had lost or the war for that matter. At first, it seemed a blessing, until the implications made her two best friends eventually think otherwise.
There was no cure.
After the second year, everyone was worried that she would never be the same. Until close to the third year, she started to remember certain things, like a brief memory of how she came to have the scar on her arm. She remembered Fred Weasley, yet did not know he was dead. During that second year, she believed she grew up as an orphan.
Harry and Ron noticed that the bad outweighed the good, but always came up short in their research.
As soon as the third year started, it was if her memory was wiped clean of the progress made. Halfway through the year, she had a nightmare of strangers she did not recognise dying. That year, she did not make progress.
In year four, pieces of her memory returned to her in fragments over a long period of time, with a great deal of space between each one.
Year five was the year Hermione Granger remembered it all.
At first, she wished she could go back to not remembering but knew that was selfish of her. In a way, she was glad that she remembered - it was like a lesson to her, that she was stronger now. Her mind had eased her into it over all these years. It didn't make it hurt any less but now she felt she could cope a little better, especially since everyone else was coping and had done for the past five years.
It seemed good the first time she thought about it - she forgot about all of the things that had hurt her.
But when she really thought about it - she realised that she was grateful, because she would have continued forget the people she loved and had loved.
Hermione was hell bent on honouring the dead by remembering them and living life to the best of her ability with the living.
Hermione Granger was strong.