Most people aren't like that, a few are.
It becomes a lot less interesting and curiosity invoking when you have such a bullshitter in your life. The interaction becomes "the lied about this, so what did they really mean". For example, my bullshitter will often have car troubles, a dead pet (that comes back to life) or medical issues whenever they don't want to show up to a family event.
I can promise you there's really nothing more deep to understand beyond the fact that they've become overly comfortable with using lies to get what they want.
Same formula across country, culture, time and people keep getting sucked in.