If we have any national fault, it is hiding our own anger from ourselves. Here is a checklist to help you determine if you are hiding your anger from yourself. Any of these is usually a sign of hidden unexpressed anger.
This is not about rage. This is about the feelings we call "irritation," "annoyance" or "getting mad." We are taught to avoid expressing these feelings and to avoid having them if possible.
Unfortunately, many people go overboard in controlling negative feelings; they control not only their expression, but their awareness of them, too.
Because you are unaware of being angry does not mean that you are not angry. It is the anger you are unaware of which can do most the most damage to you and to your relationships with other people, since it does get expressed, but in inappropriate ways. Freud once likened anger to the smoke in an old-fashioned wood-burning stove.
The normal avenue for discharge of the smoke is up the chimney; if the normal avenue is blocked, the smoke will leak out of the stove in unintended ways - around the door, through the grates, etc. - choking everyone in the room. If all avenues of escape are blocked, the fire goes out and the stove ceases to function.
Likewise, the natural expression of anger can be blocked, just like a chimney; this blockage can be disruptive to self and others. Our expressions can be stifled in an effort to protect our selves. By continually suppressing our feelings, we convince ourselves that we are not angry, even when we are. Such self-deception is seldom completely successful, and the blocked anger leaks out in inappropriate ways, some of which are previously listed.
The items in the list are all "danger signals" that negative feelings are being bottled up inside. It is true that each of them can have causes other than anger (procrastination, for example, can be due to an unreasonable fear of failure), but the presence of any of them is reason enough for you to look within yourself for buried resentments.
If you are human, you will find some. If you are fortunate, you will find few, since you will have learned effective ways of discharging them. If you are like most of us, you will have to unlearn some old habits before you can learn new ways of handling these feelings - ways that are constructive rather than destructive.
Getting rid of a lifetime accumulation of buried resentments is a major task, which is one of the goats of counseling. Whether such a process is necessary for you is best decided in consultation with a qualified professional person.