1 Deer = 100 Deer? Deer?

I am still hung on the Beer, Deer, Beers, Deer contra. I mean really. Deer in plural is Deer...right? Yet beer in plural is beers??? Why in the hell is that? I dont know why deer is the plural form of deer, but as far as I am concerned beer folows that same crazy ass rule. Heers to deer = deer and beer = beer. Damnit, it just works to well to not ...."work." This needs to be fixed.