How does one become and atheist?

The people you're referring to are confused at the very least (yeah, I actually read your question).

One does not choose to become an atheist, it's a conclusion.

Here's the thing about the human brain. It cannot conceive two conflicting truths at the same time. So while a person may grow up believing in a deity...as other information is processed there are things that begin to conflict.

Look at it this way. Ancient civilizations believed that lightning was because they'd angered a god. Or flooding. If someone rose from rags to riches, they believed that they had gained the favor of a deity. When great tragedy struck a town or village, they thought they had not been showing proper respect to that respective deity (like if a crop failed they would offer more prayers and goods to a harvest god/goddess).

Over time, as our species evolved and learned and could understand/hypothesize/experiment/recreate we learned the answers to what caused lightning, we could predict where/when/why a flood would occur. So on and so forth.

However, once that information is processed, it conflicts with the prior theory. "God did it" becomes "a chemical reaction happened because x was exposed to y". As you can see, they are completely separate truths to explain the same thing.

For a lot of people, the more we've learned through science means that a lot of the experiences put forth by the religious or explanations...become invalidated. In many cases, these means that once someone has learned a scientific reason, they can no longer believe in a god. Just like if you believed in Santa as a child but caught your parents putting presents under the tree...you stop believing in Santa. It becomes illogical as you see what really caused the event to happen (in this case receiving presents mysteriously in the morning for being good all year).

In other cases, you have people who try to patch together the two ends. For instance, some Christians believe the Creation story as step by step factual. Some believe it to be metaphorical. Some believe that it is factual, but that we don't understand the entire process. Such as perhaps the fact that the world was indeed created by God as written, but evolution was the actual process involved to fulfill that creation story. Or that one "day" to God was actually millenia-long.

A lot of what you're seeing with things where a person does not wish to believe in a god stems from the fact that there are varying degrees of atheism. For some, they become atheist because they believe that a deity has failed them or done no good for them. For others, they simply have no need of a deity. They get what they require physically, emotionally, spiritually from themselves or their friends/family, or work or volunteering. For others yet still, they take a look at the deities shown by past and present religions and are horrified.

For instance, the god of the old testament flooded the earth killing off innumerable living organisms, people included. He is shown as a wrathful god who has the firstborn sons of Egypt all slain, condones slavery, rape, murder. There are multiple instances were quite a few of us read the Bible then have to set it down and go /what/?

But I would bet that those people you see/hear saying they do not want to believe in god simply mean..."I do not believe in any deities, and even if I could do so for one reason or another I have no desire to get to know those gods presented to me because I disagree with either the representation of them or what they have been credited with."

You have to go to your local atheist church. The preacher will bless you with the holy beer, read some chapters from "The Origin of Species" and "The God Delusion" and then you'll recite the atheist pledge:

"There is no God and Richard Dawkins is one of his prophets"

Then go back every Sunday for more readings from these books, taking the lord's name in vain, singing some atheist folk songs ("all things bright and beautiful, evolution made them all") and concluding with the traditional denial of the holy spirit.

In summary: you don't have to do anything. If you don't believe in god then you are already an atheist.

I doubt few (if any) say "I don't want to believe" - it's comments like that which lead to fundie idiots going on about rebelliousness and other similar garbage. Either you believe or you don't...they just don't.

Ask yourself this question:

Do you believe in the existence of gods?

If the answer is no, then you're already an atheist.

For me its not about wanting to believe or not, its about my brain just not being able to believe in anything supernatural.