When you think about how to make your best friend’s face in Blender, instead of listening to what they are saying.
When you make an error while writing on paper you look for the undo key.
I concur. I did that in my Algebra.
I have done it multiple times as well. 
Yeah, me too. It’s hard after using blender for so long. And I always try and press x to delete things & end up with a load of x’s on a word document.
my case was a bit diferent, I was on the kitchen, I broke a egg, and … i think you can guess
When you can`t get used anymore to say “move” instead of “grab”
I guess none of the hot keys worked . . .
If you ask your boss if you can borrow the company computers for use as a server farm. Needless to say, I got a no. What a waste of i5s and i7s though, performing menial inventory tasks my smartphone can do just as quick, and never will be used for something greater. Almost makes me sad.
Blender is definitely addictive… Whenever I see anything, I would think that, well, it would be mix of a diffuse and a glossy with a fresnel. Whatever the object may be, blender makes me think logically and understand the lays of nature in a natural way.
Each time I see a new object I wonder how to reproduce it in Cycles, and how to setup the lights, or if it is a better option to HDRi the place … (very guilty !)
When you hear somebody talk about a blender and get over-excited thinking you’ve finally found someone to discuss CG with.
Happened to me a few times.
That’s happened to me a few times as well. Also if someone mentions a blender as in the food processor I sometimes think that as well.
Yep, it’s also funny when you say something like “I teach him how to make humans in blender” and people who accidentally hear it are just like wtf xD love it
… look at a random object and suddenly it turns to wireframe.
I really think this should be called “Blenderitis” 
Yeah, it definitely should. I did that when saw a tree today, and I tried to model it it my mind. Got a couple of funny looks from some walkers when I was sitting staring at the tree and wondering how to recreate it in blender, but oh well.
when you can’t remember what it was : quadBook? N-gonBook? FaceBook? triBook? PolyBook?
When you find a glass shard’s refractions more interesting than the latest smart-phone only because there’s no android blender.
When you wonder how many ticks per second a persons logic is firing at…
… and can translate them properly into “Mickeys.”
…you see a hot girl and think ‘Nice mesh!’.