What causes someone to become a pathological liar?

There's no one answer to this question, as there can be many different reasons why someone might develop into a pathological liar. Sometimes it can be due to early childhood trauma or difficult home life, while other times it may be linked to mental illness or personality disorders. It's also worth noting that not all pathological liars are completely aware of their habit - sometimes they genuinely believe the false stories they're telling, even if others can see right through them. If you think you or someone you know may be a pathological liar, it's important to seek professional help in order to understand the underlying causes and start working on addressing them.