Where, oh where, have the little hats gone?

Remember the days when no matter how poor a man could be, he never went outdoors without a hat? Or the many ribbons and flowers and various accessories that adorned every lady's head for miles around? I don't know, perhaps you do, but it is unlikely since you would be in your 90s and have better things to do than frolic around on the internet. Anyhoo, what happened to those hats? (As in, what historically, econimically, or culturally happened that could cause hats to fall to the wayside as neccessary articles of clothing-such as shirts or shoes?) Does anyone miss them? If hats were still a common staple in the daily wardrobe of man, woman, and beast alike, what would they look like?