Why do so many people dislike Socialism?

So why is there always confusion between socialism and communism? My history teacher uses the two interchangeably. I see a lot of people doing it here as well.

Well before the Iron Curtain collapsed, children were thought that everything that had anything to do with Karl Marx's idea's was evil and bad. However they thought them that in a simplyfied way (they were children afterall), so they mixed socialism and cummunism together and forgot to teach the children that it's not the systems that are evil, it's just they leaders abusing it are.

That's why there is such a discomfort in the USA regarding talking about ANYTHING that has to do with socialism, because they think it will lead to communism and evil things... Remember, People were growing up for decades with communism as their arch enemy in the USA. I think your history teacher is still living with that fear these days and sees everything that looks even a bit non-pure-liberal as evil communism, you can't really blame him, he's only a human being.