Robert Griffin III is daring people to doubt his abilities and that he is accustomed to dealing with it.

"They doubted in High School
They doubted a turnaround at @Baylor 
They doubted a Heisman was possible
Keep doubting. It's nothing New," wrote Griffin on Twitter.

Griffin did not say his Tweet was in response to any one thing.

"I said what I needed to say, there's no need to look into it," Griffin said Thursday. "It's right there on Facebook, it's on Instagram, it's on Twitter. It is what I believe and what our household deems necessary to go out every day and be successful. That's all I've got to say."