It is essential for you to remember that the attention you give to any action should be in due proportion to its worth, for then you won't tire and give up, if you aren't busying yourself with lesser things beyond what should be allowed.
-- Marcus Aurelius, Meditations, 4.32b
"...don't spend your time (the most valuable and least renewable of all your resources) on the things that don't matter. What about the things that don't matter but you're absolutely obligated to do? Well, spend as little time and worry on them as possible....If you give things more time and energy than they deserve...then sadly, you've made the important things - your family, your health, your true commitments - less so as a result of what you've stolen from them."
* Source: The Daily Stoic by Ryan Holiday and Stephen Hanselman