Millennials are deep into their late thirties and forties now, which is exactly the age the bill for adulthood comes due in full. And one particular complaint keeps surfacing in every millennial corner of the internet: it’s so unfair that… Some of what follows that phrase really is unfair, and worth being angry about. But a lot of it isn’t. A lot of it is just the standard fine print of being a grown adult, the same fine print every generation b…