Finally, you wonder how much longer you can get by in life without a metal lathe.
You have a Flashlight addiction when: you are actually reading this thread.
..when there is a large power outage and you already have a lit light in your hand, indoors. (True story.. :D )
When you mod an AAA light to liion, don’t have any 10440, and you use your 18650 and a dmm to test run it anyway 
Everyone in your family and most of your friends has at least one light that was specifically chosen for their needs . If a commercially available flashlight wasn't perfect for them , you modded it until it was .
A very angry friend (police captain) calls me to complain. His wife just called him from her car to say that she was completely blinded by the mega light I have on the font of my bicycle, and she needed to stop immediately till she could regain her vision (I ride with a SRK mod). My response: “it wasnt me… I havent been out all day.” They just assumed it was me because Im “the crazy local flashlight guy.”
Ummm... How about when you DON'T do this because you know ALL your lights would blind you?
And when you go to the guy who sells the $150 502b and C8 lights at your local gun show and just laugh, then pull out your $12 pocket EDC that outshines them all 'to compare'.
You order 6’ of thin wall 3/4” brass tubing to make flashlights. 0:)
When the mail lady says “your house gets more packages than anyone else in your zip code—we checked.”
And the UPS guy says the same thing.
And the FedEx guy says the same thing.
When Richard sets up shop in YOUR garage to save shipping costs.
When you get a text message at 6:30AM and it’s the sun, asking you if it’s ok to come up now “Are you done?”
When the moon drops her head in shame, unable to compete even when full.
addiction? I ain’t have have no addiction! twitch twitch
When your neighbor who is 110 yards from your barn and 320 yards from your house calls and says he saw someone with a flashlight looking around your barn at 3:00AM and you were actually at your home shinning the light out the back door.
At Christmas time when your friends and family say they like the light but don’t need anymore lights because of all the ones you have given them in past years.
When you know the difference between lumens and OTF lumens
You have committed to memory the lumen drops of typical flashlight materials (or their thermal conductivities)
You have to bite your tongue when you see what other people call ‘flashlights’
When deciding which light to EDC or take on a hike becomes AT LEAST as big of a decision as deciding what pair of shoes to wear or purse to carry is to the average 17 year old girl.
When you get into a ‘contest’ of are there more shoes or lights in the house?
When you have more detailed plans for mods than for your career...
When the first thing someone says, before opening his present: how many lumens?
When the sys op at work sends you an email asking why you have visited a non work related website that discusses flashlights 37 times in the previous three days.
I told him I was pricing some public safety components and looking for user reviews.
Yeah.
When you get tired of going back to reorder, so you buy at least two of every light on the first order.
….when the lights included in your give-a-ways blow away anything for purchase locally.
….when you get frustrated explaining that 18650 cells are in fact inside laptops.
….when you can instantly figure out total voltage based on number of cells.
….when you know what mode is next.