what is the best thing you have made/invented?

Question: what is the best thing you have made/invented?
- Keywords:
  achievement,
  discovery,
  invention
Asked by anon-294519 to Emma on 23 May 2021.
- Emma Yhnell answered on 23 May 2021:
  
  I worked out that brain training computer games might help with brain diseases, I think that is pretty cool

Question: what is the best thing you have made/invented?