When checking in at an airport, no matter how rude the check-in person is to you, always smile and be nice because you don't know what kind of day they've had. You are going on holiday and they're stuck wherever they are. Be nice to them because they can re-route your baggage to wherever they feel like.
Millennials regularly draw ire for their cell phone usage. They're mobile natives, having come of age when landlines were well on their way out and payphones had gone the way of dinosaurs. Because of their native fluency, Millennials recognize mobile phones can do a whole lot more than make calls, enable texting between friends or tweeting.