4 years old in Korea is 3 years old in other countries because when they were born, they're already 1 year old.
.......that's odd I never knew that
I don't think Jiho is dumb. My little sister is like this too. Maybe it's cultural difference?
You can google "Korean age" www
Yeah, he seemed more like a 2yr old than a 4yr old. You'd think it's just a 2yr difference, but when you're that young every year makes a difference in maturity levels.
I babysit a four year old and they're not that stupid I know it's a common thing for creators to make the child characters seem super dumb I literally had to work with twenty or so junior infants (4-5 year olds) and they can surprise you with how much they know