title: What would be an example to optimize code that was supposed to work without useMemo, using useMemo()?
body: <p>In React's Hooks API, it was suggested that future react implementation may choose to forget memorized values and that the code should work before optimization with useMemo(). </p>
  
  <p>My question is, what would be a good example in which the code works without useMemo(), performs better with useMemo, and continue to work if useMemo forget memorized values? </p>
  
  <p>You can visit the original page <a href="https://reactjs.org/docs/hooks-reference.html#usememo" rel="nofollow noreferrer">here</a>, a screenshot is also posted in case the page is updated in the future.
   <a href="https://i.stack.imgur.com/2juVW.jpg" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/2juVW.jpg" alt="enter image description here"></a></p>