OK, quiz time ... This is something Millennials have a really hard time doing in restaurants. The answer: Sending food back. According to a new survey, older people are much more comfortable sending food back than 18- to 34-year olds. Just 41 percent of Millennials said they were comfortable sending food back at restaurants compared to 61 percent of Baby Boomers. And 15 percent of Millennials said they would never send food back -- even if there was a big problem with their order. (You Gov)