Notepad with Ibrahim Sani: Of mistakes & apologies

Here's a question, if you did something wrong (no matter how big or small), and you apologized for it, should people still dredge up the past and blame you for it? If people still do this, then why apologize in the first place right? 

Kevin Hart was made host of oscars, then people brought up his past, and he then turned down to host the oscars. Did his apology many years ago mean nothing?