Someone can be swayed into an extreme without consciously realizing it.
People try to convince one another that they are living life on the right path. On a subconscious level, they know that if enough people believe this, they will focus their energy towards that perception. This combined energy increases the odds of the perception manifesting.
The person doing the convincing might see their views and lifestyle as normal. For the person being convinced, it could be extreme, and therefore unsuitable. If convinced, this person will take on extreme energy and perhaps try to impose it on others.