Brain nods thoughtfully along as Mario talks. And it... certainly makes a lot of sense. And it just makes him want to figure this all out more. Brain scrutinizes the puddle on the floor. He has half a mind to set off Firaga on it, just to see what happens, but...

Mario looks bad. And Brain hates seeing his friends feel bad.

So he tables the thought to set a puddle on not-water on fire, and instead stands back up. "How about we go get breakfast?" He says, without any care that he might be abysmally wrong about what time it is. The general direction of Food was where Brain was headed in the first place, anyway, and he certainly wouldn't mind the company.