I did a quick search, and I couldn't find a thread that had this. And so, in utter disbelief, I will start it myself.
You've played too much DF when:
-you stay away from cats, not because they're bad luck, or even because there's probably vermin nearby, but because they might explode
-you can construct a building of any size, even though the only thing keeping it up is one pillar
-you lean against the walls of your house in summer, and the wall is hot. There must be magma in your house. You go get some pumping equipment and channel your house out from above, to remove the magma
-you have become cave adapted
-you actually function better when you're drunk
-you stop going to church, instead preferring to worship Toady One the Great
-you only drink alcohol, or well water when there is no alcohol
-you drink only from buckets and barrels. Mugs are decorative toys.
-you put major effort into devising creative, intricate ways to kill politicians, because locking them in their rooms and letting them waste away just isn't creative enough anymore
-you reference dwarf fortress in real life
-you dig beneath your basement and produce crafts in your home, in hopes of giving yourself a fey mood
-you have a furnace in your house, powered by magma, where you make metal weapons just for practice
-you are claustrophobic because you fear the HFS
-you figure the answers to life can be found in life's raw files
-you buy cheap magnets, take them home, and melt them into bars of iron (smelting magnetite)
-your house has ballistae, fortifications, pits, traps, catapults, etc, to protect yourself against goblins. They'll come sometime.
-when studying for a geology test, you consult the matgloss raw files
-no matter how big or strong someone is, you are always able to fit them into a cheap glass cage, and they will never be able to break out. Ever.
-your definition of a bad work day is when you have to carry stuff around
-your muscles are huge from doing your own bookkeeping
-you become stronger, faster, and tougher by learning trade skills