Did I now? What makes you the expert on my life? What your mother told you, the ungrateful middle child who walked away from a life of luxury. I had all the material possessions but don't think for a second I had it easy. Imagine for a moment growing up in a house with Bellatrix.
Slytherin doesn't mean you have to use it as an excuse constantly to explain your rude behavior. It means ambition, it means cunning. It is not an excuse to be cruel or insulting.