Anyone have any guesses as to what Quirrell's game is?

Quirrell is operating on a level that I surely don't understand. The only theory I can think of that's neither preposterous nor disappointing is that Quirrell is protecting Horcrux!Harry.

In light of the recent exchange where Quirrell asks Harry how he would hide something:

Tell me, Mr. Potter, if you wanted to lose something where no one would ever find it again, where would you put it?"

... "Well," said Harry, "besides trying to get it into the molten core of the planet, you could bury it in solid rock a kilometer underground in a randomly selected location - maybe teleport it in, if there's some way to do that blindly, or drill a hole and repair the hole afterward; the important thing would be not to leave any traces leading there, so it's just an anonymous cubic meter somewhere in the Earth's crust. You could drop it into the Mariana Trench, that's the deepest depth of ocean on the planet - or just pick some random other ocean trench, to make it less obvious. If you could make it bouyant and invisible, then you could throw it into the stratosphere. Or ideally you would launch it into space, with a cloak against detection, and a randomly fluctuating acceleration factor that would take it out of the Solar System. And afterward, of course, you'd Obliviate yourself, so even you didn't know exactly where it was."

The Defense Professor was laughing, and it sounded even odder than his smile.

... "All excellent suggestions," said Professor Quirrell. "But tell me, Mr. Potter, why those exact five?"

"Huh?" said Harry. "They just seemed like the obvious sorts of ideas."

"Oh?" said Professor Quirrell. "But there is an interesting pattern to them, you see. One might say it sounds like something of a riddle."

Assume that Quirrell was asking where he could hide a Horcrux. It's funny because all those options leave Horcrux!Harry dead. The riddle is thus:

• Voldemort must hide his Horcruxes in a place where his mortal enemy, Harry Potter, will never be able to find them.
• Harry Potter is one of Voldemort's Horcruxes.

Any takers?