External problems often require categorizing their quantity, quality, severity, or magnitude. We can perform triage to organize and prioritize by converting these logical abstractions into relative ranking.
However, internally (psychologically and emotionally), we are incapable of logically ranking each predicament or distress: an argument with your boss or spouse is equally as influential on our decision being hungry. (see Daniel Kahneman)
More importantly, we seldom recognize our emotional or psychological state, allowing it to creep into influencing our external evaluations (affecting our effects).