You feel like you did OK, but the outcome isn't what you were anticipating.
It often means you didn't do as well as you thought. There may be a slight, but correctable gap between your situational perception and reality.
Sometimes external factors mean that no matter what you did, the outcome was going to be the same. However, when success is truly related to how you interact, you have a lot of control. I think it's quite healthy to believe that you have control in most such situations. It leads to a reflection and improvement instead of a feeling of fatality due to external circumstances.
From time to time, others will give you direct feedback about where you fell short. It can be hard to hear, but it's almost always a gift. I've had this happen in interview situations, or in fit calls with candidates where they ultimately decided to choose another company or team. When you get such feedback, the extent to which you have to guess is reduced. It's enormously helpful emotionally, because guessing can sometimes lead to quite a lot of self doubt.
There have been times in the past where I did a bad job of accepting such feedback even though it was spot on. Ego is a terrible trap, but the good news is that if you're open to hearing feedback and genuinely want to get better, it gets easier to hear what you need to hear.
Giving feedback is a great service you can provide to others. The best mentors and leaders consistently provide such feedback in a constructive way. Nowadays, I feel blessed when people directly give me feedback with candor. I appreciate it much more than invoking The System that's preventing a favorable outcome, whatever that may be: the promotion quotas, or the bell curve, or the hiring constraints. It's almost always easy to deconstruct "it's the system" rationales and prove they're an excuse with counter examples.
I don't like making resolutions that much - the new year is such an arbitrary excuse. That said, one thing I'd like to do more of this year is to look for opportunities to give better feedback to others, and to avoid the urge to blame systems.