When several of your local coin shops call you to see if you have another duplicate coin someone is asking for. You respond by asking in what grade?
......when in your sleep your brain determines if you water down the dogs food for a few days, you can pinch enough cash to buy the coin you've had on your watch list for 18 days.
When your wife says "you've earned it, go ahead and pick out the car you want and let's get it for your birthday" and you realize that you can have any 2 of the 3 this year - your new car, your 1934-S MS64 Peace Dollar, or your wife. But making the decision to have any 2 of the 3 will preclude the 3rd from happening for quite some time. And the fact that driving around in a 20yr old POS for a year or two is now a viable option.
When you buy coins with posting the picture of them in one of these threads in mind, and you pass on coins that wouldn't look good in the thread
You know you have too many coins when it would take you a full week to count everything, and you're not even sure if your cataloged info even has the correct count. That's me And when your coin boxes/ammo cans are so heavy you can't move them.
When you have to find space on your first floor to store your coins, because the floor was sagging upstairs. (might be a joke, or an urban legend, but during the coin roll craze there were stories of people's floors caving in because they stored too many coins at their houses)
This is actually a really good thing! It means that you are learning to appreciate eye appeal, and are searching for attractive coins to be proud of, instead of just buying to fill a hole in a set.