That's because he lived in the jungle with only his dad for his entire life.
Meet Ho Van Lang from Vietnam.
In the 1970s, a war broke out in Vietnam.
Many of this man's family members perish, so him and his dad decided to run away and hide in the jungle.
The war ended one year later, but they had no idea.
So they stayed living in the jungle for 40 years.
They foraged and hunted for food and even made a hut out of sticks.
One day, people collecting firewood found Ho van Lang and his dad.
They were shocked to hear that the war had been over for 40 years.
Eventually, they were taken back into civilization and adapted pretty well.
Because Ho van Lang had been in the jungle for so long, he had no idea what a woman was
He was too young to remember his mother or sister ever being alive.
In 2021, at age 52, Ho van Lang sadly passed away.