Beliefs are a consequence of atheism but not intrinsic to atheism? Hmmm... Clever play of words, but is that how the mind actually works? If I don't have any belief about elves living in my back yard, I am simply ignorant of the idea. To say I have no reason to believe about elves in my back yard assumes that the idea has crossed my mind. If the idea is in my mind, the mind is such that it naturally forms a judgment about it. I need prior beliefs to make judgments. As long as the God concept is present to your mind, you cannot claim that your atheism, in any sense, describes a mere lack of beliefs about God. Only a person raised in isolation of all theists and theistic ideas could ever claim the title of atheist as you conceive it, and that, I judge, is a very unlikely idea.

I think that perhaps you are not being as careful with the word "beliefs" as you might.

It appears that you are asserting that the introduction of a concept - elves, in your example - instantly creates a belief system around them.  It is unlikely that you would be introduced to the concept of said elves prior to your experiences with your back yard; therefore, it is possible (and entirely likely) that you would initially develop an elf-free understanding of your backyard.   The mind does not so much rely on beliefs as much as it searches for patterns.

Of course, if you were raised in a household that valued the theory of elves even above the realities of the back yard, then your interpretation would apply.