Apparently not! On my visit in November, there they all were, still trying to do it, most of them without success. So I was asked time and again to do it again ... and again ... and ...
Funnily, girls seems to pick it up quicker than boys, regardless of age.
But children would come running up to me just so that I would show them how to do it again.
Another amusing "trick" I picked up from the Morcombe & Wise show was with a paper bag. the illusion is to throw an invisible ball into the air and catch it in a paper bag. As the "ball" hits the bag, it makes a sound ... naturally, but when the kids look in the bag, there is nothing there.
Of course, fans of Eric Morecambe must have seen this trick thousands of times. The illusionist clicks the fingers of the hand holding the bag to make the sound of something landing inside, but if done correctly (and I have had a lot of practice), it can keep children puzzled for a very long time.
It works well on aircraft if you find yourself sitting next to a fractious, impatient child - and the airline even provides the paper bag (the sick bag), but make sure it hasn't been used!