Really, it's been shown mathematically.
"The model is: ([W + (D-d)] x TQ) /[M x NA]
The equation is broken down into seven variables: (W) weather, (D) debt, (d) monthly salary, (T) time since Christmas, (Q) time since failed quit attempt, (M) low motivational levels and (NA) the need to take action."
Doesn't that just pick up your spirits? It only gets better after this.