Understand that 'wear out' implies a slow process, not an immediate breakage.

Gradual Process

'Wear out' can refer to invisible damage; something can look fine but not function properly.

Not Always Visible

'Wear out' can be used metaphorically to describe overuse of non-physical things.

'Wear out' can refer to physical tiredness as well as mental exhaustion.

Sometimes 'wear out' is exaggerated to express extreme fatigue, not actually being unable to move.

Being 'worn out' is subjective; what exhausts one person may not affect another.