Julius Caesar is told to beware the Ides of March, and he ignores the warning.
A soothsayer warns Caesar that he should be careful on a certain day.
A soothsayer bids you beware the ides of March. (Act 1, Scene 2)
Caesar asks him to repeat it, asks to look at him, and then dismisses him as a “dreamer.” Caesar decides to leave it to the “augurers,” his priests who divine the future from animal entrails. He is pretty convinced with how they respond.
If he should stay at home today for fear.
No, Caesar shall not. Danger knows full well
That Caesar is more dangerous than he. (Act 2, Scene 2)
Caesar’s hubris means that he actually thinks that he is above danger. He is beginning to believe his own hype, about him being turned into a god. He is not afraid of the ides of March, because he thinks he is untouchable. Nothing can hurt him. Even when he gets a warning that something can go wrong (and Romans are a superstitious folk), he still counteracts.
It turns out that the soothsayer was right—Caesar was in danger. His enemies, including Brutus, whom he trusts, feel that he is getting too big and powerful. They want to take him out before he becomes too strong and they can’t get to him anymore. Caesar gets a warning to stay home, but little heeds it. Instead, he goes, and there is a great conspiracy waiting for him. He is about to be assassinated.
Interestingly enough, Brutus knows this. He does not encourage Caesar to stay home. The warning is just a reminder that Caesar actually is vulnerable, and it is time to act. Now that there is a public warning, they have the perfect alibi. People will be expecting something to happen.
Here is the film adaptation of that moment: