You did not choose most of what you believe. That is not an insult, it is arithmetic. By the time a person is old enough to evaluate a value, they have already been living inside a hundred of them, and the ones that arrived earliest are the hardest to see, because they do not feel like beliefs at all. They feel like the floor.
The useful question is not whether something was inherited. Almost everything was. The question is whether it survives inspection. A value you chose will hold up when you look directly at it. An inherited one tends to change shape, or it produces an odd defensiveness, or it turns out to belong to a specific person whose voice you can still hear when you repeat it.
So the work begins with an inventory rather than a demolition. You are not trying to throw anything out yet. You are trying to find out what is actually in the room, and whose it is, and whether you would keep it if it were offered to you today for the first time.
What usually happens, when people do this honestly, is not a dramatic rejection of the past. It is quieter than that. Two or three things fall away almost immediately because they never had any weight of their own, and the rest get held more deliberately, which turns out to be the difference between carrying something and being carried by it.