Why you can't do what you should do

A potential answer comes from Robert Dilt's logical levels of change, modelled in a hierarchy.

1. Purpose (What else?)
2. Identify (Who?)
3. Values and beliefs (Why?)
4. Capabilities (How?)
5. Behaviours (What?)
6. Environment (Where and when?)

Change that begins at the bottom does not affect the next step up unless you make an effort to climb. Change that starts at the top will filter down naturally.