Cultural Difference between Korea and the USA

In my subject opinion and also object opinion, Korea is one of the most Polite and Humble country.
There is two reasons that i said like this.

First, Korea has a lot of Polite expressions.
I'll show you For example about 'Hello'. We have 3 different ways to say 'Hello'

An-yŏng-ha-shm-ni-ka : For Older Person (Super Polite)
An-yŏng-ha-se-yo : For Older Person.
An-yŏng : For Younger Person.

Second, Usually Korean doesn't brag their ability.
Even though in a Interview they try to showing their strengthens indirectly.