Plaintext Productivity
Whatever system I have (tried to) used over time, I've run into the following challenges:<p>1. how to deal with old tasks (are they relevant anymore? should they be removed?). 
2. connecting tasks to their related source and needed information to act<p>For the former, the accumulation of old stuff has consistently led to less and less usage of the system and as a result to a continuously decreasing trust in that system. Adopting a new solution has given the feeling of a better system with better chances to success; but it has mainly been about having a (temporarily) new clean inbox.