We're all highly susceptible to influence.
Why? Because we are social and self-preserving. We don't just do best in community, we actively need and seek it out.
Thus, it's no wonder that we want to be part of a community.
And to fit in that community, we take cues of behaviour and mindsets from others around us, especially those who are respected or, at least, somehow elevated in the community.
Since this is all hardwired into us, and we've been picking up cues since we were born, we get really good at it. Practically an instinct.
Which means that it's also impossible to be free of influences.
What I learned is:
The first thought that enters our heads is a result of external influences, whether it's upbringing, culture, the people I hang around with the most, etc.
We can call this programming, conditioning, internalisation, or what we like, but it's kind of in-built and very difficult to override.
What's really important is what we do, say, and/or think after that first thought appears.
That is what makes us who we are.