There are two state of minds of Anderson Silva

There's a Serious Silva who is unstoppable in the octagon and there's a Clown Silva who puts himself vulnerable by putting his arms down then dance in the octagon.

Sonnen's pre fight trash talking made the Serious Silva fight Sonnen.
Either Weidman got into Silva's head at the pre fight weigh ins or simply Silva treating Weidman as if he was a lesser fighter like Maia or Bonnar made the Clown Silva fight Weidman. 

That's how anyone can beat Silva, make Silva get arrogant and cocky as Clown Silva and your probability to win the fight increases.

For the older cappers, this is reminds me of the famous Roberto Duran "no mas box" fight

You mean the serious Silva that was dominated by Chael for 23 minutes in the first fight and the entire first round in the 2nd fight. Weidman is on another level than Chael and Silva found that out the hard way tonight. Weidman was the better fighter tonight, end of story.