If it doesn't challenge you, it won't change you.
"The human mind is a set of information-processing machines that were designed by natural selection to solve adaptive problems faced by our hunter-gatherer ancestors."
你如果出色地完成了某件事,那你应该再做一些其他的精彩事儿。不要在前一件事上徘徊太久,想想接下来该做什么。