Can't Keep Track Of All The Verses
Dre's been in the game for nearly 30 years, so there's no way that he can keep a hold on all his verses. The recording process has taken so long that most of his ideas are probably lost in translation by now. Not to mention the fact that Eve, Rakim, Raekwon, Busta Rhymes, Joell Ortiz and many, many more were all on his Aftermath record label at one point. Dre's got too much on the brain to be worred about Detox.