Every item has 6 characteristics that in combination determine the age/damage status.
Max age x2
Max damage x2
Current age x2
Current damage x2
Single age flag
Damage state
The x2 indicates that it can have different stats for activated and non activated.
Single age indicates that only goes from OK to destroyed other wise it goes through stages of 0=OK to 5=destroyed.
Current age and current damage get incremented with either time (measured in TICKS) or dame from combat. When the current age/damage exceeds the maximum ten the damage state is incremented by 1.
So an item with a current age of 50 and a maximum age of 10000 can still have a damage state showing 0=OK but not be perfect.
If you leave an item on the ground then it will age, even if it is a no damage item like godly armour or titanium dagger.
There is no known way to reset an aged/damaged item that is not able to be repaired.
I hope this helps rather than confuses.