Confluence... I was floored when I realized it can't support duplicate page names in separate page heirarchies.

eg. You can't have a page called Engineering > Electrical > Test Procedure and another page called Engineering > Mechanical > Test Procedure, because the two "Test Procedure" pages are considered as occupying the same namespace.

> I don't want to waste cognition because they re-invented the flat tire.

Fantastic metaphor. It just got fast-tracked into my personal lexicon.

I worked on a Trac-based project long ago and I thought for sure when I moved on it would be to greener pastures. But it was simple and if you used it certain ways you could get a hell of a lot out of very little.

Its biggest problem was that the parse and display code were entangled (same problem I had with AngularJS), and it made writing addons an exercise in re-implementing features of the parser over and over again. But I heard they fixed that quite a while ago.