User blog comment:Thailog/Ep. 201 "Happy New Year!" discussion/@comment-68.81.5.150-20120429034334/@comment-76.105.240.251-20120429035338

Who said Dick quit and then become Nightwing? Maybe Jason Todd attempted to take the mantle early, which inspiring Dick Grayson to take up the mantle of Nightwing. Even if Dick took up the mantle of Nightwing around 16, two years is plenty of time of Jason to "die" and Tim to take up the mantle of Robin.