In Scene 1 of Act III in the play Julius Caesar, why does Artemidorus fail to get Caesar to read his warning?

In this part of the play, Caesar come off as a selfless
man concered with the problems of others before himself.  As he is walking to the
Capitol, Caesar is presented with several requests to give his attention to their
petitions.  When Artemidorus advises Caesar that he must read his first, for it is of
direct importance to Caesar himself.  Caeser brushes him off and says, "Whatever
pertains to myself I will deal with last" (line 8).  Perhaps he truly is a selfless guy
or possibly he didn't like the aggressive nature that Artemidorous insisted he read the
petition.  Regardless, the petition was an attempt to save Caesar's life. and because he
ingored Artemidorous, he did not hear about the conspirator's plot in time to save his
own life.