I don't.
There's lots of different wibbly-wobbly magicky wagicky stuff going around, and wizards are just doing their best approximation of it. I don't necessarily view the DM as an absolutely omniscient information dispenser, maybe the vampiric warlord/evil wizard/mind flayer has access to some weird, wacky magic that no one understands. If the player has their character express an earnest interest in figuring out how that weird magic works, I'll turn it into a little side quest or a downtime activity.