A lesson I wish I learned earlier:
A useful personal knowledge management system is one that helps you create more and better stuff. Everything else is fluff.
How I would do thing differently:
1. Create an intention (how will I know my system is successful?)
2. Use one markdown tool for at least 6 months
3. Focus more on output and adding value to society
4. Reevaluate in 6 months whether I met my intentions