The little legs had firm ground beneath them, he was delighted to note that they were completely under his command, they even strained to carry him off wherever he might desire, and he already believed that the final alleviation of all his grief was imminent.
As Gregor tries to chase after the head clerk from his office in an attempt to keep his job, he realizes for the first time that he can move by using his legs. He describes dropping to the floor for the maneuver as feeling comfortable with his new body for the first time since transforming into a bug. His human brain takes stock of his situation, enough to feel pleasure that he has a way of moving with ease but frustrated that no one else can understand him. Though his awareness of his circumstances suggests the disastrousness of his situation, he believes his sufferings must soon be over.
Gregor had no idea what excuse was used that first morning to put off the doctor and locksmith, because as no one could understand him, no one thought, including the sister, that he could understand them, and so he had to content himself, whenever his sister was in the room, with hearing a sigh now and then or an appeal to the saints.
As Gregor becomes accustomed to life as a bug, he begins to take pleasure in the few ways he can, such as eating and eavesdropping on his family. Though he tries to communicate with his family in the beginning, he quickly realizes that no one can understand him even if he can still understand them. While his family likely thinks he has no consciousness of the situation, his awareness of his surroundings and his family’s feelings towards him highlight the loneliness of his new existence.