When it comes to matters pertaining to this world, it is never possible to be completely satisfied. If you seek only physical pleasures, regardless of how much you do have, you will always be lacking.

But when you make it your main ambition to serve the Almighty, you will feel a sense of wholeness. The pleasure of serving the Almighty is so intense that it is above any other pleasures. Hence when you attain this, you are missing nothing.

Sources: see Rabbi Levi Yitzhak of Berditchev – Kedushas Levi, Parshas Tetzaveh; Rabbi Zelig Pliskin’s “Consulting the Wise”