Defining core principles and values

It was recently suggested, regarding defining my own choices independently of others, “Perhaps what matters most are your own core beliefs you choose to stand upon in creating your life.”

So when we speak about living by our core values or desires or core beliefs, how do we define them? I see them changing, I have questioned some of them and they don’t look so “true” anymore, and from the work we do here, seems like I could choose to desire new values.

But this process is still based upon the values that I currently have, which are changing and conditioned by my upbringing. Like I could not have been physically active, experiencing physical strain as a core value, but that would be very much the result of me not having a habit of regular exercise. If I did, then it may well be that my values around it change.

So again, I am feeling a bit lost when it comes to anchor myself to my true core values. I see everything is available, yet nothing is really fixed but a bit wobbly. Some further insights on this would be really helpful because I would then be able to get clearer WHYs for my actions. Thank you!