Persuaded

I can't understand how the characters are so easily persuaded in Julius Caesar. Caesar was presistent to go to the senators at first. Later he was convinced by his wife to stay home one moment, but decided to go again in the next. His mind changed so quickly. If Brutus could so easily agreed with Cassius and stained his hands with Caesar's blood (as shown in the picture below) then had hehe talked with a supporter of Ceasar instead of Cassius, would he had support Ceasar instead of joining the conspiracy against him? All the characters seemed to be unsteady and easily influenced. Their minds could be changed easily by acts and schemes. So far in the book, no men had act entirely loyal to one decision without wavering.