I don't agree that structure leads to happiness, it is God and doing his will no matter if that means it is a structured will or unstructured will that leads to happiness. Job certainly didn't have structure when his world collapsed, but he still sought God and happiness through him.
Structure doesn't always mean "good things at certain times"
You have structure in many non fun places. In prison, you have a certain time that you eat, a certain time you sleep, a certain time the guards beat you up.. Its hectic at first but in time you KNOW that certain things happen at a certain time and you begin to set your life schedule around the structure of your environment.
Jobs life wasn't that hectic, it was just tramatic, he lost everything in a snap of Gods finger.. then hit a long draught. His structure revolved around nagging visits from his wife and "friends".
Take a look at Children.. the ones who are well adjusted and happy are the ones who live in a what environment? Structured.
Children who move often, are uprooted and tossed around without having any real schedule to their lives have a difficult time relaxing and adjusting to society because structure provides security and on down the line ultimately leading to happiness.
If you bring a an abandoned child into your home, and provide a set bed time, a set wake time, and set meal times for that child and NEVER say anything to him/her about it... before long that child begins to feel naturally happier and they do not even know why.. it's because of structure.
God doesn't appear and give us all the elements of life in a basket. We don't say "God.. only you can make me happy, I refuse to accept it from my home or my family or anything else." We should rather say "Lord, who formed the Universe by Your word, who has given me family and friends that love me and has placed structure within my life.. I thank you."
Summary, Structure provides those things, yes it does. God provides structure. Nothing on this earth comes to us that does not pass by His hands first.
God Bless,
PaulDavid