When you can program a digital timer for 24 separate events and keep them all straight by memory without the instructions.
When you schedule all family vacations regardless how far in advance around your grow cycle.
someone said this but the truth is....
when you know your neighbors schedule better then them!
you have more invested into a room in your house no one ever gets to see then you do your television and car combined.
you're a man who believes the only food a man cooks is on a open fire but you take up baking becasue you want to make your own edibles!
you research the best cookie sheets and determine your wife's are inferior so you hunt down the best air layer cookie sheets on the market becasue you keep burning up your damn cookies.
you get x-ray vision when your partner comes in your garden and you can look right through them and stare at your plants.
you use the potential of spider mites as a excuse to stare at your plants all day long and look at every inch of them, twice.
you already decided you will quit your job if they ever ask you to travel during a cycle.