I am sure by now, everyone who follows this thread, and others (of course), know about the "phantom balls" viewed from the tee, when no one has hit yet.
Now, phantom balls, if you want to call them out, are not so phantom anymore...
When recently playing with 2 others, a fourth ball appeared on the green before anyone hit their approach shots. Once on the green, and as each hit their approach, the 4th ball remained on the green for all to see... (note-3 players, but four balls)...
edit: No, there was not a 4th player who quit. The "mystery ball" is one of the white ones. The balls that is difficult to see is my pink/yellow volvik.