Probability In Everyday Life

A few friends and I were discussing palmistry when the following bit of conversation happened

Friend 1: Macha, show me your hand again.. oh you have a simian crease!

Me: Hahaha, doesn't Simian mean monkey or something??

Friend 2: Best monkey man! But wtf? I can't believe we are discussing this stuff. How can you believe in this garbage?

Friend 3: But you know chicks like such stuff..

Friend 2 (with almost 0 reaction time): Does your Mom also like it?


Friend 1: Simian creases are damn rare da.

Friend 3: Balls. I know many people who have it. My dad and uncle have them. Its not rare at all...

I later found out that only about 3% of the population have them. What that lead me to understand is that Friend 3 might have a misconceived notion about something simply because he was exposed to outliers i.e. 2 people close to him having the simian crease without even knowing it.

I wonder how many wrong notions I have.. Hmmm...