In law, as in life, stepping back from one's own mind is the key to understanding all things.
When one is caught up in one's own mind, it's impossible to see oneself and one's world clearly . . . objectively. A lawyer is tasked with seeing into the mind of his opposition. To do so requires exorcising himself from himself . . . at least to the extent that it allows him to enter the hypothetical circumstances of another.
An overly emotional or egotistical lawyer is his own worst enemy, as he is trapped inside his own mind with no eye out. I've seen the aftermath of this lawyer in and out of the courtroom. Such a lawyer does not act in his client's best interest.