How this happens
Nobody decides one day to stop knowing their own wishes. It happens step by step, and every single step is sensible. You take on the task because it is due. You stay because it is a bad moment to leave. You do the training that makes sense on a CV.
After a few years you have a career that looks coherent from the outside, and inside the question of how you actually ended up here.
Why the question is so hard to answer
Whoever orients themselves by other people's expectations for a long time gets very good at it. That is not a weakness, it is a skill. It only has a price: the instrument you read other people's expectations with is more finely tuned than the one for your own.
That is why the question what do you really want so rarely helps. It asks for an answer from an instrument that has not been used in a long time.
Step 1: describe a day, not a goal
Goals quickly sound like what one ought to have. A day is harder to fake. Describe a completely ordinary working day in a year, if it goes well. When do you get up, what do you start with, who do you talk to, when do you stop.
Step 2: separate whose standard it is
Go through the description and mark every point: does it come from you, or did you take it over. From parents, from the industry, from a manager you admired.
This is not about throwing out what you took over. Much of it is good. It is about recognising it, so that you can choose.
Step 3: cross one out
Take a goal that is not yours and cross it out. Only one. That is more uncomfortable than it sounds, and that is exactly why it works. You make the experience that you are allowed to decide.
Step 4: test it with one question
For everything that remains: if nobody ever finds out, do I still want it. What survives that question is almost certainly yours.
What you do with the answer
Tell one person. Not as an announcement, but as a sentence: this is what I want. As long as a direction exists only in your head, it stays negotiable.
And expect the answer to change. That is not a sign that you found the wrong one. It is a sign that you looked for it at all.