Living in the ad agency space for basically my entire career post university has taught me this lesson over and over. Defining what success is before we set out to do it is important.
It seems pretty obvious in an agency/client relationship. If expectations aren’t matching then it’s really hard to deliver work that has the same perceived value.
But this might even be more important at a personal level. Defining success for yourself can take so much pressure off what you’re trying to achieve since you have clarity on where you are going.