I had a nice sensation of middle-agedness when I picked up the kid from his tech camp at my alma mater.
I remember being at the exact same spot 30 years ago. Then I had a completely different problem set which most likely involved social situations and the question of what the hell would I do with my life.
My social situation has solidified considerably in recent years, but I still ask myself what the hell am I doing. Having kids in the picture helps answer the question.