Is there such a thing as an optomistic atheist?

Of course there are optomistic atheists.Only religious people would assume that an atheist must be a pessimist.I guess they think that itis a sign of depression that they don't believe in a higher power.Or because they believe nothing happens after you die that they are negative people.Or maybe it is because when a religious person trys to convince an atheist that there is a G-d an atheist gets annoyed they think that the atheist is sad because they ae without G-d.