Atheists don't really care what you believe, and don't go out of their way to convert someone.
------
From my experience that is an overgeneralization. Most certainly there are atheists who DO care what you believe. There are atheists who will go out of their way to try to convert others to their way of thinking - I can think of a few that I know personally, who make no bones about their feelings of superiority because they follow science vs some imaginary God. Sometimes that feeling of superiority leads them to an elevated sense of ego because they feel that their knowledge or non belief makes them more rational, somehow better - and I have heard these same people speak with derision about people who are believers. They use labels like uneducated or ignorant to define a believer. In that sense, there are some atheists who are exactly the same as any religious fundamentalist who also portray an elevated sense of morality or superiority for their beliefs. Militant atheism is the same as militant religions. Whether you knock on a door hoping to convert someone, or try to belittle them or shame someone into not believing in God - both methods are based on an agenda of conversion.
I could care less because I fall into neither category - but the methods are obvious on both sides. Not all church goes try to convert you- neither do all atheists .