Dave talked about this at length in his interview on "inside the actors studio". I can't find a decent link right now, they all seem to be chopped short. First thing I feel is relevant is that his mom is well respected as a professor of African & African-American studies, so he grew up with an educated understanding of the black experience. He constantly has his head on a swivel trying to keep his influences in check, and you can see this in his recent specials too. So as he was entering his 3rd season of Chappelle show, certain things didnt set right with him. For instance, he was told to replace a black female character with a white one, even though the sketch took place at the Apollo (which has a historically black audience) to increase mass appeal. He was told a character he would play should wear a dress. Now this one is important because his dad had told him some time prior that you have to establish a boundary for when things stop feeling right. When you see that line approaching, get out. For Dave, it turned out the dress was that boundary. He said that many black comics before him ended up wearing dresses, and it just didn't feel right that they should have to. I think it was an Oprah interview where he asked, "why do I have to wear a dress to be funny?" He saw it as somewhat of a turning point for when a black comic no longer owns their material, but is now just a Hollywood tool. For him, it was no longer a comical performace of daring ideas, but a mockery of the black comedian himself. He has talked in other interviews about the toxic Hollywood culture, which is why he chooses to stay grounded by living in Ohio. People with strong personalities still go crazy in Hollywood, and Dave sees that as evidence that something is not right with the culture. So when he was asked to wear a dress, he felt he would be getting pulled too deep into that mire, bucked the contract and laid low in Africa for 2 weeks to start sorting things out. He came back to comedy slowly, and his ability to weave that deep introspection throughout his material is what makes him still such a prolific, laser-dodging comic.