Temperament is not something you can really help I guess, but your reaction to anger is another thing. I think frustration is something that is bound to grow with age, which is why those who are perpetually angry on the train are middle-aged people (okay this is just a plain observation) haha. My parents are a convenient example; I never understood why they harp on the most trivial matters, for one thing they seem to hold a grudge against anyone who blocks their path literally. It's sad that nobody nowadays truly embraces the definition of living free - even if it's not explicit, we all hold grudges somehow. I'm not going to be idealistic and claim that everyone should start thinking of rainbows and clouds and fields of magnolia, it's hard, it's real that anger finds its way to our doorsteps as an unwanted, cruel audience.
I've changed quite a bit from how I approach controlling my anger from the people around me these past few years. Even if I'm angry my response would be very mild or rather my (normal) face is just... a poker face. Mainly because I've learnt that keeping your emotions veiled would affect people in a less detrimental way and also because getting angry is of no use whatsoever. And well, I don't think I've much reason to feel angry too because up till now (in a fortunate way) my life has been pretty uneventful.
On a completely irrelevant note, I'm quite sad that World Cup season is coming to a close because I quite enjoyed the heated atmosphere and staying up with my family to watch the matches ahaha even though I'm not a soccer fan.