Doubt can play tricks on a person.
There is a psychological phenomenon called 'conformity'. It happens a lot, and to everybody I know.

This is how it works. If several people tell you something is true, then doubt about what you thought was true changes to suit the others.
This happens within groups of 3-8 people. So, if 20+ people said something differently, then conformity has less impact

Conformity happens because humans have two (amongst others) strong social desires. "We like to be liked, and like to be right".
These desires influence us to conform with the others.

In the above post, it says "people kept calling me Samantha and I thought my name was Samantha".
To me, that points to conformity.

This happens to me all the time. For example, I meet several friends for a bicycle ride. We originally planned to go to the next town. But along the way we stopped for a rest and someone said, "lets go back for a coffee". At first nobody showed any sign of agreement. Then another person said "okay", then another, then another, then everybody agreed to go back for a coffee. I knew it was conformity, but I wanted to go to the next town. So I said, "I am carrying on to the next town as planned"; and off I went all alone on my bike.

Sometimes it takes courage to be true to ourselves.