One thing I've noticed is far less desire and ability to "binge game".
Pretty much gone are the days from my very early 20s and late teens where I could and would look forward to playing games for hours on end. I'd sit down with one (good) game for 3, 4, sometimes 5 hours at a time.
Or if I had a bunch of free time, spend most of it gaming. Play one game for 2 hours, switch to another for an hour or two, pop in another for 2 hours after that, with only a few quick breaks in between.
Those days are pretty much gone. Sure, games like Civ or other deep, involving strategy games MIGHT hold my interest for a couple of hours.
But now, after usually no more than an hour or hour and half, I'm simply ready to move on to another activity.