I don't believe in gods because... Alzheimer's disease exists.  Well, that's really an oversimplification:  I don't believe in gods because of a multitude of individual reasons, and I never fully believed many of the things told to me as part of my Christian upbringing.  But when my grandmother died of Alzheimer's -- the savage, early-onset, rapid-progressing form that can be inherited genetically -- it hit home in a very deep way that we humans truly exist on our own.

Growing up as a gay teen in the bible belt, I'd become increasingly jaded on the idea of revealed truth: believers were so certain that they were right that they couldn't see how obviously wrong they were.  Even so, I still clung to Deism as I entered college: I felt sure that there was a paternalistic supernatural intelligence of some sort, who was happy to see us prospering and thriving in the same way that parents are proud of their child taking its first steps.  I also felt a fuzzier sort of hope that death wasn't the end -- that everything works out, when it's all said and done, and that everyone eventually finds a happy ending in some unspecified afterlife.

Contemporaneous with this, my grandmother was diagnosed with Alzheimer's.  At the time of diagosis around 1991, she was barely 50; her hair was just starting to gray.  As I grew from tween to teen, my grandmother began to lose her short-term memory and become more absent-minded.  At this stage, it was easy to dismiss the disease's effects:  "Oh, that's just Granny's memory acting up again: remind her a few more times and she'll be fine".  Some people with Alzheimer's never progress beyond this -- they die of some other age-related illness before it gets worse.  But early onset Alzheimer's doesn't merely strike at a younger age:  it also progresses faster than standard Alzheimer's.

By the time I was entering high school, a mere 5 years after her first diagnosis, my grandmother's long term memory started to go.  She forgot how to take care of herself, and she had trouble with recognizing familiar people.  Helping her in day-to-day living became too stressful for my grandfather, so my aunt stepped in.  Then it became too stressful for my aunt, so they hired a part-time caretaker.

If it were just a matter of caretaking, I wouldn't have thought twice about it and it wouldn't have pushed against my residual beliefs.  However, something strange happened at this point:  she started to change radically from the person we knew and loved.  Her intellect, which had been subversively feisty for a woman of her era and upbringing, gave way to much more menial conversations.  Her behavior changed radically:  she lost her social inhibitions, becoming uncharacteristically forceful and rude when she didn't get her way, and shockingly libidinous when she was cheerful.  Then apathy started to set in, and the extremes of emotion slowly muted into a forlorn sort of perpetual grumpiness.

By the time I was graduating high school, my grandfather was still in denial about the fact that she needed full-time care.  Her speech had degenerated beyond conversations or even sentences, and all that was left was babble, delivered in a very snarky and bitterly sarcastic tone.  He brought her to the family business each day, and she would babble and pace and wander the office all day long, each day showing less and less emotion and recognizing fewer and fewer familiar faces.  After I left college, my grandfather finally placed her in a care center.  The perpetual grumpiness faded, and the babble grew less and less frequent, until both stopped entirely and all that was left was the endless wandering.  She refused to stay still long enough for the hospital staff to feed her, so they had to restrain her at meal time.  But she never showed frustration or outrage at being restrained:  without a hint of emotion she just silently squirmed, like a restless infant that forgot how to cry.

Not long after I left college, she fell while wandering the hospital hallways and broke her hip.  After that, she no longer had any interest in wandering, either.  She just passively sat in her chair in the hospital, apathetic to everything going on around her.  Eventually she refused to swallow food, and my Grandpa didn't have the heart to prolong things any further by putting her on a feeding tube.

She died of starvation in February 2003, just a few days before Valentine's Day and a mere 12 years after being diagnosed with Alzheimer's.  By that point, I'd abandoned Deism for agnosticism, and agnosticism for atheism.  My grandmother's Alzheimer's was far from the lone triggering event in this progression, but it did inform my decisions at each step of the way.

In comparison, though, giving up on the idea of gods was the easy part.  The toughest blow was abandoning body/soul dualism for materialistic monism, and with it any hope of an afterlife.  After all, if an afterlife had existed, what good would it do for my Granny?  Piece by piece, the disease had ravaged everything that made her a unique human being:  her memories, her personality, her sense of identity.  Even if she had an immortal and immaterial soul, there was nothing left for the soul to do:  she was long gone.  If the soul left her body a long time before her death... then who was in her body, when she had those brief and increasingly rare flashes of recognition?  And if the soul left her body at death but somehow retained her identity... doesn't it constitute soul-torture to see your body acting out, harming your loved ones, with no power to reign it in?  And if her personality was something separate from her soul... then what good is her immortal soul, if it's not her?  None of these possibilities is heartening.

It didn't help me that her illness and death happened in a patch of my life that was already rough enough without any added tragedy.  Eventually, though, I learned about secular humanism.  And as I pondered science and history and freedom and progress and spontaneous order and technology and capitalism and open source software... I realized that there's plenty to look forward to.  There's plenty of hope in this life: no afterlife required.

My new motto: "Sometimes the world sucks.  But we're working on it!"

As a youngster, I was a huge science geek whose best birthday gift ever was an encyclopedia set called "Growing Up With Science".  I originally wanted to become an electrical engineer, until my family bought our first PC when I was around 13.  From that point forward, computers were my passion, and throughout high school I knew that I wanted to go on to college and study Computer Science.  After a long road that went places I absolutely never planned on -- including dropping out of college and stocking groceries at Wal-mart -- I kept studying independently and eventually landed my dream job in the Silicon Valley.