a serious question. please don’t think i’m trying to be mean. i truly am just curious

my older brother is currently 2 years clean after about 10 years of shooting heroin. it hit my family really hard and made everyone pretty depressed because my family is super close. lots of love in this house. however, i noticed over the years that i’ve grown very cold towards addiction and addicts as a whole. i don’t feel the sympathy that i used to feel when i would see my brother lookin...ya know. dopey and dumb. all i can think, is how did we have the same supportive, understanding, and selfless parents? how did we both grow up with 2 amazing older sisters that would do anything in the world for us? only for him to make the choices he did? i noticed that even now, i look at him with cold eyes. our relationship was never that great, clean or not, but now he’s cleaned up and i just... don’t feel bad. like at all. am i awful for this? is this a normal response to this kind of thing? i don’t hate him. he’s my brother. and when we were little i wanted to be just like him. but now it’s almost like he disgusts me. :/