Snape clenched his fist closed after Harry left, glaring at the pensieve as if it was all the bowls fault for what had happened. He didn't know why it was added in there, maybe to remind him of where he had come from, to remind him of his past and what to work away from.
It still hurt so much...

'Leave him ALONE!' James and Sirius looked round. James's free hand immediately jumped to his hair. 'All right, Evans?' said James, and the tone of his voice was suddenly pleasant, deeper, more mature. 'Leave him alone,' Lily repeated. She was looking at James with every sign of great dislike. 'What's he done to you?' 'Well,' said James, appearing to deliberate the point, 'it's more the fact that he exists, if you know what I mean…' Many of the surrounding students laughed, Sirius and Wormtail included, but Lupin, still apparently intent on his book, didn't, and nor did Lily. 'You think you're funny,' she said coldly. 'But you're just an arrogant, bullying toerag, Potter. Leave him alone.' 'I will if you go out with me, Evans,' said James quickly. 'Go on… go out with me and I'll never lay a wand on old Snivelly again.' Behind him, the Impediment Jinx was wearing off. Snape was beginning to inch towards his fallen wand, spitting out soapsuds as he crawled. 'I wouldn't go out with you if it was a choice between you and the giant squid,' said Lily. 'Bad luck, Prongs,' said Sirius briskly, and turned back to Snape. 'OI!' But too late; Snape had directed his wand straight at James; there was a flash of light and a gash appeared on the side of James's face, spattering his robes with blood. James whirled about: a second flash of light later, Snape was hanging upside-down in the air, his robes falling over his head to reveal skinny, pallid legs and a pair of greying underpants. Many people in the small crowd cheered; Sirius, James and Wormtail roared with laughter.

Snape shook his head, riding the memory, the flashback from his mind. That bloody meddling Potter, poking his nose wherever he went, everywhere he liked. He, like his father, never got into trouble, not once! Snape seethed to himself, Harry was a weak waste of space.

He sighed and sank into a chair, resting his chin in his hands as he closed his eyes and lost himself in another memory, one he was more fond of, but it also made him a little more bitter as well.
After a long afternoon of working on their final essays for Potions, she had just smiled at him in such a way that he had leaned forward, ever so slowly and had kissed her, and Lily had kissed him back, ever so gently and then she'd smiled at him again and kissed his cheek before leaving for the night.
Then she'd never returned to him.

Snape sighed once more, bitter. He hated remembering the past.