Thirty-somethings and 20-somethings often mingle in the same places; they have similar ranks at their jobs, have some overlap in their friends’ groups, love the same bars, and even date each other. And while these two age groups are only a decade apart, they are light years apart when it comes to their values, their experiences, and their perspectives, which is why 20-somethings tend to drive 30-something’s a little crazy. If you’re in your twenties, hoping to make a good impression on your older colleagues so they’ll consider you for better positions, you should know about this list. If you’re in your thirties and think you might “accidentally” spill your coffee on your twenty-something-year-old coworker’s cell phone one of these days, you should know you’re not alone. Here are things 20-somethings do that drive 30-somethings crazy.