We have goals of the kind of person we want to be, but even if we achieve parts of that goal, we don’t fundamentally change. That’s because our ideal image is typically stereotypical. We don’t imagine being us as a doctor, so much as a broad image of a doctor. This can be both good and bad.
The good is that having a broad stereotype to go after means you can get there in multiple ways. It doesn’t close you off as much, and you can be more comfortable with a type of specialization within it. For example, say you want to be a surburban-home living engineer; that still leaves a lot of options of which location you’ll live and what sort of things you’ll design. The bad of having a broad stereotype as a goal is that it might not feel like you. Humans aren’t simple beings. Even the least complicated of us have nuances and subtleties, and we rarely fit into the “typical” perfectly. Even if you achieve becoming an engineer and living in a suburban home, it might feel off, because it’s you that’s the engineer.
We idealize the future because we want to believe we can improve things, and we can! But even improved, our future will still have difficulties and conflicts. We aren’t going to be wonderful people all the time, and sometimes things come up out of nowhere. It is so important to have goals and work for them, but we also need to realize that they probably won’t turn out like we want. That’s not to say we won’t be able to appreciate the outcome! Rather, if you’re asocial and slightly misanthropic, you might become more generous and connecting a person, but don’t force yourself to be some outgoing people-lover you’re not. Achieve your goals, but keep yourself in it.