I'm looking for a fic I read years ago. I'm having trouble finding it; really hope it wasn't deleted from the internet :(
It starts out with Naruto waking up in the Konoha Hospital and none of his memories. Sakura is there, and when Naruto asks how he knows her, Sakura answers something along the line of "we're lovers."
extra spoilery info
Naruto's amnesia is actually recurring, something Sakura knows well, but it's hidden from Naruto until near the end. Sakura has had to deal with Naruto losing his memories again and again for several years, and not once has Naruto fallen in love with Sakura again... Until now.
Naruto starts getting headaches and it's only a matter of time before he loses it again. When he finds out there a procedure that could cure him, he jumps at the chance, even though there's a strong chance it could kill him.