Just so everyone knows which side the other is on, it's fair. But comparing lack of wisdom teeth with the lack of belief in God is weird.
It's not weird. Some people don't find it necessary to trumpet their particular beliefs or lack thereof to every passerby. I find it odd that you believe there is some nefarious purpose behind this. I mean, do you want the guy to come up, offer his hand and say, "hi, I'm an atheist. I thought you'd like to know."