This is why we fight all of the time:

You and I, we're the same

Stubborn, foolish, a little selfish

But most importantly, we both need to be right.

All. Of. The. Time.

Impossible, huh? There's no way two human beings can always both be right.

Funny thing is, we know that. 

We've acknowledged it.

So why is it that neither of us ever give in?

Refer to similarity number one.