In Book One Chapter Six, Harry reads Albus Dumbledore's wizard card. On the back of the card it mentions he "is particularly famous for his defeat of the dark wizard Grindelwald in 1945" I wonder if this is an important thing that may get brought back into Book Seven. Let me explain my thinking. In Book Two at Nick's 500th Deathday Party the cake says he died in 1492 so that means that the year is currently 1992. Also 50 years previously it was 1942 and Tom Riddle was reaking havoc as the Heir of Slytherin in his sixth year (I think). Once he graduated Grindelwald would still have been at large and he drops off the face of the Earth once he kills Hepzibah Smith. Is it possible that while his whereabouts were unknown, that he hooked up with Grindelwald? I have been pondering this for a long time and would dearly like this question answered.