In my many years of life, I find that one of the greatest pain relievers is solving one puzzle or the other. At the end you find that most of what ever pain you had was done. I never limited myself to what sort of puzzle I tackle. Perhaps it may work for you too. Here, the hope is, as was done before, yousolve one and give one.
So here goes: A set of twins that arrives at the same time, but as one progresses, the other declines.