The answer to that question is false
Yes. Because Cassius was the one who started the events that led onto Caesar's death and eventually on to his own death. Brutus did not like that Cassius was being un-loyal towards his own brother-in-law and therefore spoke up about it when they talked in the tent it act 4.
Intelligent, Wasn't that bright is sarcasm, like, Wow that was smart (aka stupid)
MAY BE WRONG, ALSO LEARNING MYSELF