mindful of one thing
In the early church an Abba or an Amma (spiritual father or mother) would give a beginner a maxim to think about, and be mindful of all day (including memorizing it). This is wisdom not information.
For example, ‘Want to possess nothing with as much desire as those who want to posses everything.’ Diadochus of Photike (5th century).
Speaks to our materially possessive world.