Percy Weasley had always been a part of the large family, and with that upbringing, he was not used to being alone on important days. He was surprised when on Christmas Eve, he recalled that this was the third year in a row that he had been alone for the celebration. After this realization, he was even more aware of the solitary involved in all his actions. When he filled the teapot with water, he only added enough water for two cups of tea for himself. When he made his dinner that night, there was only one serving. When he went to sit on the sofa in his sitting room, he was all alone, no joking brothers in the background, no shouts or scoldings. Just him.
It was not as though he had not been aware that he was alone on the previous Christmases spent in this flat, but he had never felt the emptiness of it as acutely as he did that night. As he watched the snow flurrying outside of his window, he thought about how he could even begin to rectify the situation between himself and his family. His absence had left a gulf of discomfort, and he wondered if he could ever swim the distance.
More and more, he had been musing about how his life would have gone if he had remained with his family instead of choosing to focus solely on his career and placing his trust entirely in the Ministry of Magic to do what was right. Now that the Ministry of Magic was undeniably corrupt and evil, Percy imagined himself going back in time and erasing all the regret with which his choices had rewarded him. There was no way for him to traverse that great expanse now, though, and Percy was not sure that he wanted the inevitable smack of "I told you so" in the face.
So when he climbed into bed that night-not even bothering to be excited for the next morning, which held no promises of Christmas gifts or the delicious family dinner-he was alone, and not even in his dreams did his family return to him.