The 72nd Day

Do you know the twelve signs of the Chinese zodiac?
On Sunday, I went to dinner with people who were born in the year of the rabbit. 
There were people of the same age and 12 years old younger.
It was interesting that she distributed in a category of the Chinese zodiac. these sentences are not clear. please try to elaborate.



干支って知ってる？
日曜に、卯年の人たちが集まる会に参加した。
同じ歳の人と12歳年下の人がいた。
干支でカテゴリー分けするのがおもしろいとおもった。

I miss my life in Korea.

It's been 4 years living in Philippines. I visit Korea for vacations, once or twice a year.
When I was in Korea, I worked hard and learnt (past tense) many things (plural).
It was a very busy life back then. 

Here, I'm not working anymore and there nothing is so interesting to learn,
It's a very slow life.
I love to live here but sometimes I miss my previous life in Korea.

the word "shaking up" has confused you, i believe. "shaking" basically is a verb/an act of moving an object in harmonic motion to correct/neutralize a situation. but in this sentence it means like, when something goes wrong/ not working/ not up to the mark, then you shake/correct the current position/ situation. its is like an old rusty bolt which you try to open but cannot. then you hit/rub/vibrate the bolt to remove the rust and free up the bolt.