Cicero's Plan to Kill Caesar

The plot to kill Caesar then from what I can see seems to be the worst kept secret. Is it something that he should have seen coming and something maybe he should have paid a bit more attention to? There were rumours of conspiracy and assassination constantly apparently. He refused to have a bodyguard. He didn't want to live like that. It would have been really interesting to see what would have happened if Caesar had lived beyond 44 - how things would have changed.