My friends don’t believe in me 😭😭😭😭

Ok. I really want to be a surgeon, like really bad. But when I told my friends this they just laughed and said “ok sure” , “you would kill all your patients” , “there’s no way you can do that” and , “i wouldn’t want you to be my surgeon” and I know it sounds petty but it’s my dream and I get pretty good grades (I have all a’s and one 87) I know it’s the beginning of the year for some but my school started 2 months ago. I’m always trying really hard in my classes. I don’t understand what I can do to prove to people (my friends) that I can do this. If I even talk a little about it they all just laugh. I don’t know what else I can do. I talked in circles but do y’all have any advice?