Around the dinner table, the conversation was lively. Thank you but for now, the forum has been archived.
I think aged Cooper was in season 1 episode 2 or 3 (depending whether you count the pilot as an episode). I don't remember there being any explanation for his aging, so it's a happy accident how it matches up with the Return, although, as you said, Laura hadn't aged.
It was because young Coop dreamed that he was older. But Laura was still young