Please note; the backstory in this is actually what Quirrell is recounting. He reminds me a lot of myself in his school days, I have done it this way also to build his character later in the story. Hope you guys enjoy!
It was the first day at Hogwarts for Quirinus. He had moved from Britain to Switzerland at the beginning of first term; having lacked so much self-esteem, he knew he wouldn't fit in from the start. One thing was always on his mind, 'why was I chosen as a Ravenclaw? I have no brilliance.' Indeed this boy was one of the most brilliant in the school; however his timidness from previous bullies and and doubt from his parents caused him great trouble with his self-esteem. It also meant he wanted nothing more than to prove himself; nothing more to be noticed but how would this be when he didn't know a single person and was too shy to talk to anyone?
Being the new kid isn't easy, especially when you've had a background like Quinirus's; it was his first day of Hogwarts; he was terrified. He didn't know whether he would ever have a single friend, whether he would ever fit in with anyone; his self-esteem being so low didn't help at all; it was so low even the strongest man wouldn't be able to pick it up with his teeth. He walked about the halls, as he made his way to the Great Hall for the sorting ceremony; it hadn't been a very good start; the moment he arrived via boat to the gates of Hogwarts he knew that he was different; while everyone chattered amongst themselves, the small, pale boy kept at the back of the line of first years, hunched over as he shook slightly with fear; of course he wasn't the only nervous boy but to him, everyone else was brave. Everyone else had nerve and was a lot more brilliant than him. He piled into one of the boats with two other first years, however had no nerve to say anything; he liked it this way, there was no way he was going to make his first impression as the coward he was who stuttered uncontrollably to a point where they would barely understand him. Once he reached the gates of Hogwarts, his eyes lit up brightly though he shook with fear as the thoughts of being the odd one out ran through his mind. He was led into the Great Hall for the sorting ceremony; he was relieved when he was relieved to be one of the first few called as this meant no one would judge him if he were sorted into the house of Hufflepuff; the house, as he heard it, for the weak.
The sorting hat was placed on his head; for a moment it thought, about a minute passed when it bellowed, "RAVENCLAW!"
"Th-th-th-there m-m-m-must b-b-b-be a-a-a m-m-mistake." he stuttered quietly.
The sorting hat said nothing as it was removed from his head. Quirinus stood to his feed and shuffled his way to the Ravenclaw table. What just happened? Why was he sorted into the house he'd heard was the most brilliant of them all? There was no way he was worthy for such a table. He shook hands with many very shyly, only wishing he could go to his dorm and sit on the side of his bed to read more on Defence against the Dark Arts and Potions. He didn't want to be in the crowd; he wanted to fit in but didn't want to make an idiot of himself. Once sorted, the great feast begun; being the kind boy he was, he waited until everyone in eye's sight had at least one piece of chicken before he, himself took the tiniest bit.
A boy next to him smiled at him. "You're not gonna have any more of that?" he asked. "There's plenty to go around."
Quirinus smiled timidly and took some more, his hands shook vigorously and he hunched over his plate and ate in secret, hoping no one was watching him. Once the feast ended, the announcements were made and they hurried off to bed; everyone but Quirinus who stayed back and waited for the last person to stand up. Although he didn't realize it; he was one of the most kind-hearted boys anyone could meet; though he had no confidence. He knew he would be a very misunderstood character from the beginning. What happened to this boy throughout his years at Hogwarts? Well one can only find out as we skip onto his seventh year when this lonesome, pale boy started his seventh year at Hogwarts.
Quirinus recounted his life at Hogwarts on his way back in September; he could only think about one thing- studying hard to get his mind off students. His first few years hadn't started out that great at all; he was a major subject to bullying and didn't think anything would change. As he walked down the halls, as hunched over, as timid as ever, he took note of everyone he passed; whether to avoid them or not. From his experiences, he knew all too well it was best to avoid all people; they picked at him for his stuttering; he was known as a coward; he had come to believe it to be the truth; he couldn't see himself for what he truly was at all. He decided to avoid everyone by walking up to the Ravenclaw common room; he pulled out his book of Potions and began to read up on what he already knew; he truly was a brilliant teenager. A few others entered but of course he found no nerve to say hi.
'What do I say to them? Hi or what? No Quirinus... you must not say hi... you're not good enough.' ran through his mind as he watched the people chatter about happily. He continued to read on with his book and decided not to bother about what they were doing. He deeply wished he could join them but knew he would make a fool of himself; despite receiving all O's in all his subjects; he still thought himself as not good enough because he was forever studying, whereas the others were having the time of their lives, laughing and eating candy of all sorts; secretly he waited for someone to talk to him but that never did happen.