Answer by Professional Japanese Teacher
We received this question from one of our followers on Facebook.
We’re not sure under which situation you are going to say this expression so we’re going with a generic one.
Hontoo ni yaritaikoto o miushinawanaide (kudasai).
(Please) do not lose sight of what you really want.
You can omit the part in bracket if you are using this for close friends. I hope this is what you are looking for.
If you happen to read this post, please give us your comment and elaborate further on the background of saying this.