Addendum.

This should have been included in the grab bag of thoughts but I forgot.

-If you have a pair of cool hipster glasses, you better make sure that your other friends don't have crazy weird glasses too, because when a group of you head out together with your stylish glasses on, you look ridiculous. One person in a group of friends can have fashionable frames. Maybe two.* Any more than that and you look like a walking advertisement. 

*This does not apply to Europeans. You can't help it.