I'm the same way. I like to try to figure out what's what with a whacked coin:-)
I learned though that by analyzing certain things we can figure out if a coin is an error. There are consistencies.
When we come across a coin that doesn't fit the consistencies that we look for we usually can discover that there is some kind of post mint damage that has been done to a coin.
When I talk about consistencies, I am not saying that every error is 100% identical but I am saying that the characteristics of one off-center struck coin, for example can be compared to the characteristics of every other off-center struck coin and we can look for the particular characteristics on the coins. We can then identify an error that way.
It is the same for coins struck on incomplete planchets and coins that have been struck multiple times. There are consistencies amongst all
clips" let's say that we can use to identify a genuine one.
When a coin does not fit any of the known possibilities, there would then be two choices:-) It's either something new, or its a clunker:-)
When a coin fits into these two categories, we look at where the coin came from and if it shows signs of abuse or other damages.
When we determine that a coin is damaged, it is sometimes possible to tell how. Either we've seen others like it before as is the case with what I like to call "
Dryer Coins" and others keep wanted to call "spooned" . Using those as an example, I had a friend take a bunch of coins out of a clothes dryer at a laundromat as he was a dryer mechanic, and hand them to me. I know first hand what a clothes dryer can do and I have the coins here to prove to others what the damage looks like.
Similar damage happens to quarters and halves that have seen heavy use in casino slot machines.
With other types of damage, there are literally millions of ways to damage a coin and people will fool around and try just about anything. When we can't see a hole done by a drill or a mark placed on a coin by a punch or a hammer strike etc., we have to say that a coin shows unknown post mint damage.
I've learned that many post mint damaged specimens are in a condition where you just can't tell what happened to them unless you were watching somebody destroy the coin:-)
It's fun to try to figure out what happened but sometimes it reaches the realm of the impossible:-)