how on earthHow did R.A.B fill the basin with the same potion that voldemortVoldemort had originally used? wasWas he even smarter than Dumbledore, and realisedrealized even before entering the cave that it had a potion and researched or made that potion? notNot very likely, is it? wasWas it such that the basin refilled itself? butBut that won't be any use once the horcrux was taken???