Does anyone have an answer to why some people act like seven year olds?

I've heard from people that girls don't use logic in their arguments, but have they not heard some guys talk?

This is directed at a certain person who I'm pretty sure would find some legal action against me if I actually said this to him.

I find it stupid when you start arguing that DDT is important because it kills diseases like Malaria, so it's worthwhile to keep it and destroy/poison plants, animals, and us; but the places in the world that still have problems with Maleria still use DDT, so why are you even arguing?
I find it stupid that whenever a topic comes up about anything to do with human life (capitol punishment, abortion... DDT... etc.) you always, without fail, compare us to endangered bald eagles, and ask if it's more important to save them than us.
I find it stupid when you argue facts.
I find it stupid that your most recent comeback was "You were mean to me so I don't want to talk to you."
I find it stupid that you outwardly claim and laugh about gay people and insist about how creepy they are.
I find it stupid that despite all this you're still in an AIMS level Global Humanities course.

And I'd usually follow up rants like this with a "I'm sorry, but that's how I feel", but I'm not sorry at all. Maybe I would be if you stop acting fucking retarded.