It's just what I had in mind.
 →   내가 생각했던 바로 그거야.

[예문]
have (something) in mind : '염두에 두다'의뜻

1.  The dress is perfect!It's just what I had in mind.
    그드레스는 완벽해.내가 생각했던그대로야.

2.   A: I'm thinking of making something different for dinner tonight.
     오늘 저녁은 색 다른 걸 요리할까 생각 중이야.

     B: What do you have in mind?
       어떤 걸 만들려고 하는데?