He's been around.
 →  그는 안겪어본일이 없어.

[예문]
A:I'll play a trick on him. What do you think?
   내가 그친구에게 속임수를 쓸려고하는데 어떻게 생각해?

B:You won't fool him with such a simple trick. He's been around.
  그런 간단한 속임수로 그사람을 속일수없지. 그친구안겪어본일이 없어.

※   have beeb around :  '겪을 만큼겪다'.
                                     '이미존재해왔다' 의뜻
The company has been around for many years.
그회사는 수년동안 존재해왔다.