**{SPOILER}*** He's making up for not noticing her when she was alive

He does all the things she asked of him when she was alive - like letting her see his face without the mustache. He deeply regrets never letting her see him witout the mustache and it sets him off. Because when she was alive he never really cared...until it was too late. She asked him to shave off the mustahce when they were in Hong Kong on vacation, but he never did, and she died, now he's recreating all the moments of when she was alive and asked him to do things for her. Like buy the ugly jacket he didn't like... or not buy the engraving she didn't like. He didn't really notice what she wanted when she was alive, just as she doesn't notice him when he shaves his mustache off.