Summary of "The Definition of Normal" - contains major spoilers for this fic.
A young Harry learns the everyday power of words. He's going to make the Dursleys happy by being "normal". Then they'll love him, just like they love Dudley! It's a flawless plan... right?
Harry as a young boy sought to please the neglectfully abusive Dursleys by being as 'normal' as possible, acting like other kids do and liking only the things his family approved of. He also strove for carefully manipulated average grades (which took an awful lot of study). He slowly gained benefits including a real bedroom, better clothes, and more food, and grew up relatively healthy and content. However, he still suffered from emotional neglect, verbal abuse, and shorter rations than his pampered cousin. Over time he improved his relationship with Dudley through helping him with his school work.
With this background, Harry developed a desire for normality, a people-pleasing manipulative streak, a wariness of standing out (as both over and under-achieving drew his aunt and uncle's ire), and a few psychological quirks such as a tendency to hoard emergency food supplies and an aversion to touch. He hoped to win his guardians' loving care with his efforts to be normal. However, it was not to be, and he only earnt their tolerance.
Harry didn't want to go to Hogwarts and ruin his dreams of becoming a doctor and refused to attend but was pressured into it in the end due to an intervention by the Headmaster and Professor McGonagall.