My own wtf observations from visiting the US mostly relate to money and include the tips, the prices that don't include the sales tax, and the credit card readers that still only use the magnetic stripe and sometimes no authentication whatsoever. On the first day of my first visit in 2014 (in NYC, btw) I had to google what the fuck "one dime" was.
Григорий, also people predominantly getting their phones through carriers and paying them off over a year or two. But that's probably not that unique to the US.