Youth, the old saying goes, is wasted on the young. And apparently, the data backs this up. Looking back, your 20s might seem like a carefree period of music festivals, dubious housekeeping standards, career experimentation, and generally unabridged freedom. But when happiness app Happify combed through the data generated by its product not too long ago, it found a reality that belied such stereotypes of carefree youth. According to this large, if specific, data set at least, your late 20s are likely to be the most miserable years of your life.