Always express only half your anger.
If you have an anger amount of 2, express only an anger amount of 1. If you have an anger amount of 4, express only an anger amount of 2. Etc.
What if someone expresses all their anger?
I express all my anger. This doesn't mean I always rage or lose control. I don't let my anger control me any more than the average person does. I merely express all of it.
This leads to people thinking I have more anger than I do. If I express an anger amount of 1, they think I have an anger amount of 2. If something that only merits an anger amount of 2 happens, and I express an anger amount of 2, they think I have 4. They think I'm overreacting.
I try not to overreact or to have more anger than is reasonable for the situation. So, when someone tells me not to be so angry, I'm displeased. I am displeased, and maybe a little more angry, because they're thinking I'm not dealing well. Dealing well consists of:
Having only the amount of anger that makes sense in the situation (for example, not being enraged but merely mildly mad when you drop an ice cream cone).
Not directing the anger at the wrong thing (for instance, a random person in the distance).
Expressing the anger politely, such as, "I'm angry, but not at you."
It's hard to deal well--with anger, or many other things. If someone, like me, has had to deal with hard emotions, it's important to them that they're good at it. They may feel insulted when someone tells them they're not dealing well, especially when they really are dealing well, just because they politely express all their emotion in the right time and place.