I like this, and also "I don't quite understand why [X]", which puts them in the pleasant position of explaining to me from a position of superiority--or sometimes realizing that they can't.
I guess this only works on people who feel friendly. Making them also feel superior... now they owe you a decent explanation.
A hostile person could find other way to feel superior, without explanation. For example, they could say: "Just use google to educate yourself, dummy!"
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.