i think anger is generally a product of 'our belief in the degree of control we have over our lives'.
Yes, I think my "friend" gets angry at the lack of control. He thinks the nitpicking about work, or unexpected "todo" list at work is going to ruin his life to an extent for the next several days/weeks...but even though he knows the reasons behind the anger, he still gets angry...experience and awareness don't cause my friend to stop geting angry under the right circumstances.

My friend already tried all that.