What is the hardest thing you’ve done studying/working in your job but you eventually achieved it ?

Question: What is the hardest thing you've done studying/working in your job but you eventually achieved it ?
- Keywords:
  hardest,
  job,
  studying
Asked by Han03 to Lowri, Greg on 17 Mar 2016.
- Lowri Evans answered on 17 Mar 2016:
  
  Hello Han,
  
  I’d say that the hardest work I did was at a big industrial manufacturer. The bosses there wanted to cut their carbon footprint down, but the plant is really automated. The guys running the machines there were very straight talking/no messing blokes who weren’t really interested in changing their behaviour!
  
  I decided that they’d need a really hands-off approach, so I made them a dashboard that showed the energy consumption of the machines they were each running. It massively lowered their energy use, and they were really happy with it 🙂

Question: What is the hardest thing you've done studying/working in your job but you eventually achieved it ?