“How come he don’t want me, man?”

From what I’ve heard, Will Smith’s father actually left him. This wasn’t entirely scripted. Will went off on his own rant, and the hug at the end was genuine.

His character was just supposed to shrug off his dad leaving again and he starts to but then Will goes off script. That whole speech is coming entirely from him. The hug at the end is also genuine, actor to actor not character to character.