MaranaCop:
Ok, I have never worn a real ball out in my entire life.
I wore out, cut, gouged, roughed up, and scratched lots and lots of golf balls. I guess you're not old enough to have ever play balls that had a Balata cover?
Occasionally balls were not playable even though they were brand new, because they were out of round. It's not as common today because of the materials they make ball covers from.
You have a ball ring to make sure all your balls are round don't you?
I used a sleeve of new balls every round. Each ball got played for just 6 holes. Less if I hit one somewhere it was irretrievable.
At the end of the round, those balls that were still round went into the shag bag and were used at the practice green/sand trap.