This may sound wierd but I can choose how I feel if I take the time to stop and think. Maybe it was meditation that unlocked that for me, I cant remember - just like a physical action, thoughts and emotion is a choice as well. Physical pain can be treated similarly: concentrating on it can make it nearly unbearable, but merely acknolwledging its existence as a "warning light" that is simply electrical signals interpreted by my brain changes the dynamic.
Discussion
It's not weird at all. I have observed myself doing it... But I have never worked to develop it. I think when we see it, we can't unsee, and it becomes rather authomatic. Like nostr:npub1vfxsrm6hpgmnptapa0ku8mv464e9ntzlx75lp6kfc2sd9ufzha9qqu0gmq, said yesterday, "between stimulus and response, there is a space", Everything is a choice. Our mind is powerful. That quote "watch your thoughts, they become words...(...) , by Lao Tzu, it represents what you just said, IMHO. Anyone can change how they feel about anything, if they take the time to "understand" why they are feeling it. And all of us can change, like you said, how we "feel" about anything. Feelings are not facts. And sometimes what we feel and associate to someone or something, is just our unconscious bringing up, something from our childhood or even past life's, for integration.
Some people are more emotional than others tho and are quicker to react to their feelings especially if others are responsible. I think it's important to vent your feelings but in a productive manner by telling others how you feel