bug 意指“小虫子，令人心烦的东西”，bug sb. 直译过来就是：“小虫子使人心烦”，喻指：“某事使人心烦，令人讨厌”。因此，当美国人说"I've got a problem that's been bugging me."时，他/她要表达的意思就是:"There has been a problem troubling me all the time."、"I have always been brothered by a problem."。
Shirley: Sweetie, you are anxiety-ridden all day long. What happened?
Jane: I've got a problem that's been bugging me. I really don't know what to do.
①What's wrong? You look low-spirited.
②You are eccentric these days. What happened?
③Honey, is there anything bothering you?
④I can hardly bear it any longer.
1. bug vt. 烦恼
I only did it to bug my parents.
Don't bug me with petty details.
That man really bugs me.
2. eccentric adj. 古怪的，反常的
He is an eccentric character who likes wearing a beret and dark glasses.
She put him down as an eccentric person.
His actions since that morning have been eccentric and unpredictable.