No. not just you, just you and the other gullible fools that bought that t-shirt.
Now I, as an atheist gave you a working example of how I assisted a fellow human for no reward whatsoever, simply out of pure altruism. I understand why you are doing your level best to avoid that. It conflicts with your weird belief in the tooth fairy.
No matter, if you wish, I will contact said bloke and have him post in broken engrish if you so demand. I am pretty sure he would do so.
The bottom line is that you cannot explain why I, as an atheist, would voluntarily do those things at my own expense for no reason.
Personally, I know my own motivations. But in your plain caricature of atheism, you somehow cannot figure altruism. I am wondering why that is?
Lets get something straight. Being an atheist does not equate to being immoral. (I was an atheist for a while, and my morals did not fall during that time - but that is a poll of one). The debate about the relativity of morals and how they are acquired is a landmine. I need to to tread very carefully.
I have said that is
my experience that Christian communities have better morals than communities who are broadly secular, and I used the example of New Zealand.
I also used the example of Christian individuals whose trustworthiness (a "basic" moral attribute in any society) was very high.
When talking about a specific attribute of groups of any sort, it is a fact that there are spreads from one end of the spectrum to the other. The Bell Curve.
One can find individuals and even small groups across the range. But when taken as a whole, there is a peak that sits somewhere on the measure of the attribute.
Polls and studies to find a rating may not adequately address how moral a nation is
perceived to be. Hidden corruption, and immoral unjust behavior that is well disguised, is hard to measure.
My explanation for this peak on the Bell Curve for Christians is that such groups and individuals are taught (both by their parents and by the religious community) that there are moral standards that are not negotiable. Not subject to personal interpretation. Not subject to whether an individual benefits or is to their detriment.
Can these be taught in school? Partly.
Can these be taught at home? Partly.
Can these be taught by the example of the community? Partly
Can these be taught at the religious institution? Partly.
Can these be taught by exposure to media? Partly.
Can these these teachings reinforce each other. Yes. Or cancel each out? Yes, especially if the message is confusing and ambiguous.
Who decides on an overall strategy for a set of morals? If anyone can have their say, and argument ensues, then children get mixed messages, make wrong choices, do not have a grounding in how to make moral choices and anarchy will result.
A key factor is intelligence. An intelligent person knows that there are standards of behavior that are "good". Both for them and for society. Generally they analyze their own behavior and do not engage in self-deception.
Of course, some intelligent people are just very good at rationalizing their bad behavior because their bad behavior is getting them material rewards.
Let me end here for the moment.