A blessing in disguise is a blessing in disguise.

The main thing is that you have to use dialectical techniques to explain the scientific materialist theory. When things go to extremes, things will turn upside down. If things don't go well, things will turn out well. Fan Jin won the exam, and extreme happiness will lead to sadness. These are all good examples. Things have two sides. Gains and losses depend on the choice between your pessimistic or optimistic mood and your values. What do you think?