Alright what is the difference between this trope and idiot ball?

removed the following from the anime page

• Love Hina: When Keitaro had to choose between Naru and Mutsumi and decide which of them truly was his long-lost childhood friend, who he made a promise to get into Tokyo University with and eventually wed.
  You'd expect: He would pick Mutsumi, who is not only the second nicest person to him of the whole cast in general (Shinobu is the nicest), she's the only one who does not hit him when he does something that looks wrong. It's even explicitly stated she is a female version of him!
  Instead: He picks Naru, who beats him regularly, calls him names, and once refused to study with him for fear of catching bad grades! Anvilicious is an understatement, here, people!!
  However: It could be argued that the question isn't necessarily who he would decide to make that promise with now, but rather who is his Old Friend that he made the promise to then.

because this is a clear case of Shipping Goggles / Anti Shipping Goggles. There is no "right" answer or "idiot" move here. He's chosing the one he has the most feelings for. You can argue he shouldn't have those feelings, but he does and they're for Naru. The series even explicitly stated earlier in the show that he doesn't think about Mutsumi that way.

What A Maroon!

Anyone else surprised this classic Bugs Bunny quote wasn't the Trope Namer?