One Arya-Littlefinger question in particular has bothered us since Season 2, and Aidan Gillen finally has a (foreshadowing?) answer.
Entertainment Weekly got Gillen to address an old Season 2 moment, in which Arya (Maisie Williams) was still serving as Tywin Lannister’s cupbearer at Harrenhal, and ran afoul of Petyr Baelish (Gillen) in a meeting.
Granted, Littlefinger recognizing Arya had zero bearing on the plot; it’s not impossible to imagine the moment mentioned if Arya crossed paths with him again.
Baelish certainly seemed to recognize something about the girl, though the matter was never revisited before either Baelish or Arya left the burnt-out castle behind.