AN: So this is just a series of little drabbles set throughout Neville's life, documenting his most important "firsts." This will be for the most part both as book and movie compliant as humanly possible.
The first memory that Neville Longbottom has is of his mother. He's not even sure it's a real memory, honestly. It's just an image that he carries around in his mind and thinks about when he's lying in bed at night. It's possible that he invented it, or pieced it together from other memories and thoughts. After all, he was only a year old at the time, and he doesn't have any other real memories until he's three. He likes to think it's real though.
The memory isn't anything very magnificent either. He can just see his mother's face over him. It's not her face as he sees it every time he goes to visit her in St. Mungo's, with the pallid skin and vacant eyes and graying hair. No, it's her face the way it is in the old photographs Gran keeps bound up in a leather album; all heart-shaped face and rosy round cheeks and sweet smile. In his memory her face is just hovering above him, staring down at him with the pale blue eyes so much like his own, and she's smiling as she hums. He can never make out the song, it sounds like some sort of lullaby and it seems to change a little bit every time he thinks about it. But it feels serene and comforting. It's what soothes him to sleep at night, and it's what finally powers his Patronus into a corporeal form.
It's a simple little memory, but it's the first and the best one that he's got.