Majorly idiotic responses

I am a biology major and I am applying to medical colleges. I hate admitting it in general. Seriously, I am quite secretive about my name and major in general. Do you know why? Just go on reading.

Idiot: So what's your major.
Me: I study Biology.
Idiot (good response): oh that's awesome.

Idiot (anoying response): Biology is just stamp collection for girls. Mathematics and Physics are the true sciences.

Idiot (bad response): You must have to learn a lot of stuff by heart. There's nothing difficult about Biology; it's a lot of mugging-up. (Me: Why, thank you!)

Idiot (Worse response): Ewww...I hated science. I sucked at it in High School. How can you like it? Do you like it? (Me: Of course not; I am just a masochist.)

Idiot (pretending to be smart): What's your research on?
Me: Well, I work with genes in a plant.
Idiot: Genetics!! Oh, can you clone me?
Me: Well, I could give you cancer...

Things get even worse when I mention the pre-med part.

Idiot (bad response): Oh, my grandmother has [insert obscure disease] and her doctor prescribed [insert obscure medicine/surgery]. I think my doctor is a crook, though. Do you think he's fleecing us? (Me: There's this nice medicine called Potassium Cyanide...)

Idiot (worst response): Dude, can you take a look at my [insert embarrassing organ of your choice]? I think I have a problem... (I usually recoil in horror)

Idiot (really slappable response): Doctors are even bigger cheats than lawyers. They overcharge you and then they kill you! (Ohhkkk....)

Idiot (flattering but stupid response): So what do you want to be?
Me: Umm...perhaps a surgeon.
Idiot: Oh, that's intense.
*looks at me in a new light as if he's seen a halo around my head*
Me: Ermm...I am not a surgeon yet, you know.