Caesar was winding down physically toward the end and was recovering from illness when he was assassinated. Was he aware of the plot against him, unlikely. But he was aware of the rumours that his life maybe in danger. His physical condition may have been hard to accept for a man such as Caesar, someone who had been vigorous and energetic all his life. Eitherway, had he gone on the expedition to conquer Parthia and died en route, he'd still be remembered as a great Roman.