Hmmm...I Just Don't Get It

Although I've been on this earth for its last 50 trips around the sun, it seems that almost daily, there are more and more things I don't quite understand.  In no particular order, they include: 

1. Buzzfeed
2. Four-inch heels
3. The joy of shopping
4. Why iced coffee costs more than hot coffee
5. Tattoos
6. Skinny jeans
7. Why you'd talk to someone on a cell phone instead of the someone sitting across the table from you
8. Rude people
9. Mean people
10. Candy crush

 What things most often leave you scratching your head?