When you are get lectured by someone and instead of listening, you are thinking about if your corals are placed just right- or thinking about where to go to buy new live rock to make that perfect cave so all your fish have their own little happy homes.
When your 4yr old daughter can name every coral, fish, and algae in your tank.
When your computer dies- you know you need a new one- and you still go out to get those fish that you already had planned to pick up and wait another week or so for the computer.