This is a game with song names like "Please Exist, I'd Appreciate It" or "The Murder Mystery of The Crystal Dolphin Unicorn" and yet you are questioning how a certain specific one could be applicable to real life. Don't get me wrong, i'm not calling you out for overthinking a non-sequitur, but... KU's songs' names are weird like that. It's likely that this one follows that pattern. (Correct me if i'm wrong.)
As for my personal theory on how fire resistance could be awkward, i think it's referring to, well, have you ever used a fire resistance potion in Minecraft? I imagine it would be kind of like that; that a perfectly fire-resistant (read: highest conceivable level of fire resistance) object or person would be able to float or swim (respectively) in something like lava, a substance that gives you second-degree burns in mere seconds if you simply stand near it (due to convection). And even then, i haven't even brought up the surface of the sun. You could swim into there and see what's at the center. Wouldn't it be really awkward to know that you can push your friend (or throw his phone) into lava with no repercussions at all?
(Of course, i'm just assuming that we're talking "magic object that stays at a constant temperature no matter what", rather than "spacecraft that can withstand temperatures as high as 81 °F". I'm also assuming that the sun counts as fire.)
(I'm also assuming you're still checking this after 6 days of no feedback.)