After the sorting
Harry walked over to the Ravenclaw table and sat. His legs trembled as he watched the sorting, eyes on his classmates as he searched for potential friends. Harry clapped for Ron when the hat placed him in Hufflepuff, sparing a thought for the redhead who wanted something to distinguish him and now had an entire house of people who don't expect him to live up to anyone's legacy. Harry would be expected to live up to his own legacy, Harry thought bitterly.
But first, he was allowed to eat. He had accidentally sat himself with a group of second years who were too busy catching up with one another to talk to him, a situation that suited Harry just fine. Harry could never talk well after his dissociative episodes. Harry was able to enjoy his fill for the first time since his parents died. The Dursleys' never exactly starved Harry, but he had never been able to eat as much as he would like. Now he had nobody to stop him from indulging.
After dinner was a speech that Harry sat through with barely-open eyelids, holding his head up with his hands to stop from falling asleep on the table right then and there. He didn't hear a word the Headmaster said, other than that the third floor was off-limits to anyone who did not wish to die a most painful death. Harry didn't want to die any death. Well, maybe if death meant he could sleep...
First years followed the Ravenclaw prefect, Penelope Clearwater, to their dormitory for the night. Harry was on autopilot for the walk, moving from room to hallway to room to thinking 'that's my trunk, guess I sleep here' and falling asleep on top of the blankets. In doing so, Harry missed the announcement that the first-years were to have a health checkup that next morning. He also missed out on learning the names of his roommates.