Bitch Behavior still Sucks

I recently had a certain quirk of mine pointed out. Whenever anyone compliments me, I find a way to negate the compliment.
Examples:
Compliment: “Hey I like your shoes.”
Reply: “Oh, they’re really old. I just wear them at work.”

Compliment: “You and your husband are so sweet together.”
Reply: “Yeah, I guess it’s a good thing he likes fat girls.”

Is it just me? Am I the only one who can’t just say “thank you?” It must be totally obnoxious for those who say something nice to me. If people were to keep fighting it whenever I complimented, I think I'd eventually just stop the compliments.

When did this start? I remember always being TERRIFIED that someone would call me conceited. And in fact when I was about 12 years old, another girl said something to the affect of “I like your hair, it’s really soft,” to which I replied “thank you!” The girl immediately whirled around and told everyone I was SO conceited.
This same thing is illustrated beautifully in the movie “Mean Girls.” Queen Bee tells Lohan “You’re really pretty.” Lohan accepts the compliment with a simple, thanks. Queen Bee says, “So you admit it, you think you’re really pretty?” in a snarky caught-you-being-a-bitch kind of way.

So, in an effort to become a better human, I’ve decided to just accept compliments from others with a simple show of gratitude, without the need to denigrate myself. I hate that this back-stabbing behavior from the girls of my past is still making me feel small and afraid.