And sometimes he's doing zero, either because he is sick, Chas V'shalom, or incapable for other reasons. A person can at times have big Yeridos (slumps) and he feels like a “total zero: ע ַר ַב ַה Arava” which doesn't have any good taste or smell. Just like you are not Yotzei the Mitzva of Lulav without all Arba Minim, so must a person know that in this world he should expect all kinds of situations, in order to attain Shleimus.
The holy Baal Shem Tov says that Hashem wants people to serve Him with all kinds of Avoda and situations. Your Yerida (decline) is also part of your Shleimus; i.e., when you deal with it properly and respect it since it's Min HaShamayim, and when you are not Mya'esh it gives you tremendous Zechusim.
True Story
An older Yeshiva Bachur was all depressed, because all his friends were married. His father told me that he is always getting rejected. Here comes a "no" and another "no", again and again; no hope! I told the father that: “What's wrong with getting rejected again and again? It's part of the process, and it builds you!”
