MYSTERY TIME: GHOST NOTES

All right, Tumblr, I need your help in solving a mystery. The mystery is about what I call "ghost notes", and it has nothing to do with music. So basically, I've opened up some of my posts and noticed that the number of notes is less than what the little bar below the post says it has. For example, at the time of this writing, a recent post of mine says that it has five notes, but when I open it up to check them, there are fewer than that. What's up with this?