We often notice changes in behaviours and think, "they did it before", "why can't they do it again?" Most people unintentionally confuse ABILITY (i.e., do we have the skill to do something) with CAPACITY (i.e., do we have the resources to use those skills). Ability answers our question of "Can they do it". Capacity answers our question of "Can they do it in this moment, under these circumstances". Ability is more stable and changes over time... but capacity is more fluid and