Severus Snape was not an idiot. He had come to the conclusion long ago that he was expandable and was going to die, by battle if not by one of his masters first. He was always aware of the possibility and on some level-deep down yearned for the day it came. However, as he lay in a shack alone with a portion of his neck ripped out and his blood littering the floor around him, he realized that he was not ready.
He fought against the all-consuming pain, begging and grasping for just a few more moments of consciousness, and of his life. He wanted to regale on all the things he had missed, wanted one last moment to imagine that his life wasn't his own and it was simply a nightmare plaguing his innocent mind. Severus imagined a small house with all the time in the world to brew, create and explore his limitation as well as the limitation of the magical world. He reveled in the idea of letting his mind relax, free of any shield or any necessity for occulemcy at all. He thought back to his younger years and tried to hang on to the long-dead dream of him and Lily, but even now as he lay dying he couldn't bring himself to ignore his and Lily's wrong-doings for the sake of an illusion. He couldn't ignore the horrors that had happened and the mistakes that had been made.
He let his will falter, and his mind surrender to his demise. The throbbing in his neck slowed as there was barely any blood left to pump or heart functioning enough to move it. He began to loose feeling in his body and wanted to cry desperately. His life had been taken from him before now, he shouldn't be clinging to stupid fantasies and regrets. He would never be an honorable potions master. He would never experience real love and not just infatuation. Severus Snape would never do a lot of things. His visions started to blur and the dying wizard closed his eyes before it was forcefully taken from him completely.
It was then when the door in the far corner creaked open and three young battle-scarred teenagers stood in the doorway and gaped at their fallen professor. Snape wretched an eye open for the last time to see who had disrupted his death. At the sight of his students, Severus felt furious that even now, he was being haunted by dunderheads in such an intimate moment in his life. Severus ignored the small part of him that was thankful for their company so he wouldn't have to die alone.
Nevertheless, he closed his eye again and waited for the last bites and stabs of pain to subside and for the final darkness to wash over him. But instead he felt prods at his pockets and dulled whispers. He felt them ruffle through his possessions until they stilled and he heard a shaky but relieved sigh.
Now it was becoming harder and harder to hold on to himself. He felt completely lost in his body and his mind was drifting away from him. He could no longer ponder his stolen aspirations and forced objectives. He only had his fear and a wisp of curiosity to hold onto.
Then, severus registered the coolness in his mouth and a soft liquid trickle down into his fragmented throat. Suddenly, Severus was gone from himself, and the fate of his life rested on a naïve war-hero and a potion.