Seinfeld and pants

So, today I had a thought that could have shown up on a Seinfeld episode. While I was in the process of "ringing out my wet sock," as my grandfather would say, I had a thought. Why do we refer to pants in the plural form? We wear socks and shoes, which, there are two of each, and we wear a shirt. So, why do we not wear pant? True, you could say because there are two legs, but, would not the same be true for shirt? Hence, my question to you all is, why are pants so special to get the extra "s?" I am interested in your thoughts, but please try to resist researching the idea and shoot for something original first. Then look it up to see if you are correct. I have not looked it up, so I am not sure there is a right answer.