Ethan's Notes
Keeping a plain-text journal for six years
One file per month, one heading per day, all in Markdown. Six years in, the whole archive is 4.2 MB and greps in under a second. Every app I tried before this either died, changed its export format or started charging for search.
The only rule that has survived: write the entry before opening anything else in the morning. Everything else, tags, templates, links, turned out to be procrastination dressed up as organisation.