What is fashion?

I found this video at YouTube and it presents some interesting answers to the question I have been thinking about all week: What is fashion? I haven’t figured out my answer to that question yet. Instead, I will share some of my favorite explanations from the video with you:

“Fashion is having fun with clothes”
“Fashion is your own style”
“Fashion is art you wear”
“Fashion anticipates, and elegance is a state of mind… a mirror of the time in which we live, a translation of the future, and should never be static.” / Oleg Cassini

And of course I found some explanations that I don’t agree with. Two of them are:

“If you are not in fashion, you are nobody” / Lord Chesterfield
“We live not according to reason, but according to fashion” / Seneca

So my question to all of you is: What is fashion to you?