If we focus on negative emotions, the ones like irritation or anxiety are more sneaky. I don't tend to notice them the moment they arise, and when I finally do, they've already poisoned my mind and it's much harder to get rid of them. Anger, on the other hand, is such an immediate and strong emotion that there's nothing sneaky about it. It won't go undetected but rather acts as this kind of mindfulness alarm. The moment anger arises, my mind shines this spotlight on it and it loses meaning and kind of just vanishes. If I, say, make a big mistake or break something, the anger does arise, but I immediately realize that it already happened and getting angry over it is just additional negativity on top of an already bad situation, and I then just let go of it. It's not that I repress it but rather I simply just don't feed it. You can't really stay angry for much longer than seconds unless you start telling yourself a story to maintain that anger. It's mostly optional.