Gladio could understand that sentiment. Memories were indeed very precious. It was why he was sat where he was allowing this strange girl to draw him. The fact she reminded him of someone he couldn't quite name probably had something to do with it as well.
On the Train
He sat still, relaxed and calm. Strangely it was helping to settle his mind. The confusion that had been clouding his mind since he opened his eyes and found himself on that platform was slowly fading away. So he wasn't sure how long they were sitting on the floor like that but it seemed all too soon Naminé was done and showing him the picture. Gladio turned his head to look and he grinned. It was pretty damn good. "It's amazing. You've made me look better than real life. That's a talent."