We form personal preferences quickly and rarely revisit whether we still believe them to be true. As a result, choices made in our past slowly become part of our identity.
The first time you make coffee for a friend, you ask how they like it. The second time you might ask again. By the third or fourth time, you're just going to make their coffee in accordance to the preferences they've previously expressed.
This is because we decide our preferences based on a brief period of experimentation. When we're asked how we like our coffee, we almost always defer to our default answer, rather than pause to reflect on what level of sweetness we'd enjoy in that exact moment.
Drinking sub-optimal coffee may not be a big deal (for you), but other forever decisions we make about ourselves can severely limit our growth and range of experiences.
When we use labels, like "I'm introverted" or "I'm bad at math", the process of brainwashing begins: the perception we hold of ourselves shifts from a nuanced truth (I like meeting like-minded people but I'm uncomfortable at bars) to a fixed fiction (I hate meeting new people) that's easier for us to digest.
The more we repeat these half-truths to ourselves the harder we commit to self-identifying with labels that aren't quite right. Introverts commit to identifying as introverted, bad students commit to being bad at math, and unhealthy people commit to being unhealthy. All because they've made forever decisions about themselves based on a tiny sample size of self-experimentation.
Forgetting how malleable we are, both physically and mentally, limits our potential to change for the better.