First of all, a fan of Harry Potter Books? Guilty as charged.
The stories have many fascinating magical objects with intriguing charcteristics. But I am sure all creative people like writers will find a Pensieve, or somthing simialar really alluring. I mean, when ideas come rushing to your minds, and you find no way of jotting them down with a speed that match their flow... do you pine for Pensieve? Some way of storing a few strands of thoughts, may be separating from the others to process them one at a time?
Or is it something else you start desiring in these moments? Some other, less magical, but more useful, practical, real object may be?