You ever noticed that Idealists philosophize funny? I mean, they all think that we can never through any possible experience become completely certain of the actuality of external objects!
And don't even get me started on those fucking Empiricists! They think they're better than Idealists, but they're just as immodest. Have you been around an Empiricist right after they read Hume? Woo boy do they puff up their chests and start audaciously denying whatever is beyond the sphere of their intuitive cognitions!