When I was young, one of my life goals was to be a calm, wise, old-soul type person who didn't panic when things went haywire - just assessed the situation and dealt with it, unruffled. Since that was a tall order for someone who was excitable and prone to overreaction back then, I broke it down into smaller bits like "take a deep breath first, then react," "consider your options, then react," and "consider that the worst option probably isn't the most likely, then react." By never taking out the "then react" part, I avoided feeling like I was not being true to myself, and (with some amount of backsliding now and then, of course) just kept working on it.
I don't know that I had a time frame for that goal per se, other than a vague sense of "before I'm old and retired and don't have energy to do things;" it was just a "someday" idea. To my surprise, I realized recently that I seem to have attained it without even noticing. Work has been a little rough this year, starting with changing positions and feeling like an utter newbie where I had been the go-to person on the team, to finding out one of my goals would be delayed for a few years due to a pre-req I'd overlooked, to finally getting into a very rarely offered training and then falling sick the week before (I masked up and went anyway, because it's that infrequent). Each time, though, I realized that the urge to get angry and rant and rave or seethe about the injustice of it all just... never arose. After literally decades of internal work, my reaction was more a sigh of acknowledging the situation wasn't what I wanted, and then looking at how I could make it work.
It is weird changing your image of yourself. You know, that quick boxed summary of yourself that you give when meeting someone new that you'll probably be around a lot. I knew I had a temper when I was younger; I knew that if something pushed me over the edge, I'd run the gamut of loudly angry, quietly angry, then simmering resentment until something overrode it, so I'd include that in my self-intro. It wasn't until someone on my new team pointed out that they'd never seen or heard of me being angry (it's not a huge office, so gossip gets around) that I realized they were right; I wasn't that person anymore. And while it's cool to see how years of work has paid off, and I'm a generally happier person overall, it's weird knowing there's a different you that no longer exists.