My MD & were chatting at the end of my appt (we always trade book recs). She noted how her 20-30 something kids can't read a novel, watch a teaching video longer than 2 min, or remotely grasp the idea of age/aging in their future. Complexity of thought & ability to problem solve an issue too. Gave me insight into the 20-something person who beta-read my mystery novel. My middle-aged readers had no problem following the plot & really enjoyed the older characters.