He had told Harry not to come back and visit the mirror; he had told him that men had gone insane because they looked in the mirror for so long that they forgot about the world. Harry had taken his advice, but he himself had not. He was wiser, he told himself, he could stop coming to see the mirror whenever he wanted to. He just wanted to see them once more; he just wanted to see his family as they used to be when he was younger before disaster after disaster struck.
Harry had asked him what he saw when he looked in the mirror. Albus had looked down at the boy and hidden his sadness and replied that he saw himself receiving a pair of socks. Harry had accepted the answer and left the room, promising that he wouldn't come back. He hadn't.
Dumbledore had lied, like so many times throughout his life, he had lied. He had lied to the people that he loved, always trying to hide his true feelings from them, something that he had learned from his mother. There were so many things that he hadn't said to those that he loved.
After visiting the mirror for almost a week, Albus decided that it was time to stop. His mother and father were long gone, buried in the ground decades ago along with his little sister. Sweet little Ariana, she had been so kind and patient and loving, taking her potions without complaint. Aberforth rarely spoke to him anymore; it was like there would forever be a wall between the two of them. But even though Albus knew that he needed to stop coming back to the Mirror of Erised, he found that he couldn't.
He wanted to stare at his mother and father and sister and brother forever. His mother, Aberforth and Ariana would always be in the front, along with him, and father would always be standing in the back, one arm across the shoulders of his mother and the other across Aberforth. He would smile down at Albus with pride, sadness and regret.
His mother had always been a proud woman, she never slouched and she rarely showed any emotion. She wasn't one to reveal what she was feeling but every time that he saw her in the mirror, she would give him the smallest of a small and put her hand on his shoulder. He would reach up to touch her hand but wouldn't feel anything.
Ariana would always be smiling and waving at him, making silly faces in the hopes that she would be able to cheer him up. She'd tug on Aberforth's robes and point back at him and giggle. She had died at such a young age. Aberforth would look at him with brotherly affection and ruffle Ariana's hair. His brother had never looked at him like that. Aberforth didn't consider him to be family. Never had, never would.
Albus Dumbledore wanted his family back very much.