Yes, the instinct.. We were introduced to soy-margarine when I was about 10-12 years of age. I refused to eat it, as I couldnt take the texture of it. Kind of stuck to my palate.
So my mother had to buy butter, just for me, I believe it somehow saved my eye-sight, as I was the only one of us that never needed glasses.
I also refused to have low fat milk, remember taking plenty of cream in it, to my mother`s despair. :)