A Behavior takes place when Motivation
to do something and the Ability to do the
action combine, then a Prompt triggers
the action to take place.
If any of these are too low or missing, then the behavior does not happen.
If you are highly motivated to do something, but not able to, then nothing happens.
If something is very easy to do, but you don't care "Meh", then nothing happens.
The prompt is what triggers the decision to take place or there is no prompt at all.
So if you wonder why somebody does or does not do somehting, this helps you understand why.