Why do people think that atheists are Unhappy?

I am an atheist by choice, I come from a very religious Roman Catholic family. My beliefs are mine and i never try to " Convert" anyone, I hate though when Christians especially baptists think I need to be saved, Saved from what ? Hell? What exactly is hell? where is it? I guess it really cant be much worse that what we have now. i don't believe the fire and brimstone bullshit no one has ever been there and came back with pictures of hell or came back with a t-shirt saying My Grandparents went to Hell and all i got was this lousy t-shirt, I am a very happy person I have two great kids who are High School grads Honor Students Both were Student body presidents, Both have great jobs, I have been married to an incredible woman for 25 years. I even have a kitty cat that i love very much, I am respected in my community for the good things i do/ By the way we are all atheists by choice. and very happy. The main reason is we do worry about where we are or are not going when we croak. It is unimportant us about that, We do not have to live like " good christians" nor do we have to read a book of parables and fables to determine our lives, I DO NOT push my beliefs on anyone, i have seen so many unhappy christians,Worried about what the preacher said worry about the hundred dollar bill they HAD to put in the plate to by the pastor his rolex, So dammed worried about where they are going when they croak. Why worry at all? Just be happy. Enjoy life to is fullest. Love your family and love yourself. Be kind to others, Do not judge a person by whom they want to share their lives with even if it is of the same . Do not be jealous of your friends and family and most of all remember "It is not what you think of others it is what others think of you"