A : I decided to save money.
     - 나 저축하기로 마음먹었어.

B : What's up?
     - 웬일이야?

A : I need a lot of money after retirement. That idea crossed my mind.
     - 은퇴하면 돈이 많이 필요해. 그런 생각이 떠올랐어.

B : That's a good idea.
     - 좋은 생각이야.