how come all guys are stubborn?

Some maybe stubborn but not all. Let us not make a sweeping statement. My boyfriend is not that kind.

I don't think all men are stubborn but a lot of men have to much pride to do certain things so it comes off as being stubborn. I have a saying that stubborn people know other stubborn people.

my boyfriend is stubborn but so am i. we are pretty much equally stubborn

I think this seems like a pretty huge generalization. Many guys are stubborn and do stuff what they think is right. I feel it gives them a feeling of superiority and air of independence. But the same holds true for gals too. You find really stubborn ones among them too.. I just feels stubbornness does not depend on gender only but more on how a person is.

I second your girlfriends thoughts. But cannot genelarize though, but the majority fo the guys fall under the stubborn category. I feel they just want to show that they are superior to girls by being stubborn. But life is all about give and take.