As an true atheist I do not feel that I need to have the restrictions of religious people and feel no need to?

pretend I have. Apart from breaking civil laws and risk imprisonment I feel free to take life as I choose and not to worry about other people or their feelings. Am I right in my attitude? Why shouldn't I tell people the truth about themselves or shag another mans wife if that is what I would like to do? As an atheist I know that I am only here once and I intend to take from this life anything that I can get. Do others think the same as me?