You know you’re a **newspaper reporter ** when you interrupt a phone conversation with your mummy to say, “Gotta run. I just got a really great homicide.”
Your turn.
You know you’re a CPA (or in my case, work for a CPA) when your best friend has to schedule her wedding (if she really wants you to be in it) for after April 15th.
You know you’re a programmer when you correct your significant other mid-pillow talk to explain the difference between equals and equals-equals.
You know you’re a law student when you wake your SO up by talking in your sleep about torts.
You know you’re a physics major, or in my case a RadCon tech, if you can say with a straight face: “I’m going to assume that the shape of a horse is a sphere, to simplify my calculations.”
You know you work in a medical lab when you void instead of piss.
You know you’re a consultant when you dial 9 to “dial out”…when you are at a friends/family house.
You know you’re a songwriter when you cut your wife off midsentence while she’s talking about how her day at work sucked so that you can go write down a great lyric fragment that just crossed your mind.
We must suffer for our art.
You know you’re a plumber when you can go off on someone for trying to use teflon tape when clearly pipe dope is the way to go.
You know you’re a garbageman when you can look at a broken garbage bag crawling with maggots and think: “I wonder what they’re cooking for dinner tonight?”
You know you’re a college student when you have a 10 page paper due on Tuesday, and Sunday night you remember, and think: “I’d rather do 10 beers tonight than write 5 pages and be half done”.
Not me, but people I know
You know you’re a driver when your boss asks you to make a last minute trip to pick something up that is 2 hours one way, at night, after you’ve been driving all day and you think: “I’d better pick up a box of Red Bull”.
You know you’re in factory maintenance when you know the exact spot you need to kick to get the floomsis machine running again, and when it comes to talking with management you know that “reset” is a perfectly good euphenism for “kick.”
[sub]BTW, Scotty lied. Even at Warp 10, the Enterprise wasn’t in any danger. He just didn’t want to replace all the dilithium crystals that got smoked whenever Kirk did one of his little joyrides.[/sub]
Doesn’t quite fit, but:
You know you’ve been working with a computer too long, when (1) you make a mistake and try to CTRL-Z it, and (2) you are trying to search for something in your room and you go CTRL-F.
:smack: Happened to me on numerous occassions.
You know you’re a chemist when it really bothers you that your kitchen measuring cups aren’t accurate to within 0.1% – hell, even 1% would be nice.
You know you’re a medical student when people show your their intimate body parts and your reply is “umm… think I got a lecture on that last week…”
You know you’re a [profession] when…your name is Leon. 
You know you’re a musician when you call every job you get, music-related or not, a gig.
You know you’re a clinical microbiologist when people ask how your day is going and can say “same shit, different day”, and mean it literally.
Right, because a mathematician would instead say with a straight face: “Well, that horse is clearly homotopic to a sphere, so we can just…” Some mathematicians might draw a diagram to prove it.
You know you’re a government contractor when you’re sitting alone in your office building on President’s Day* because all the military and GS people you work with have the day off and you don’t.
*or Labor Day, or Veteran’s Day or…
According to my Physics college teacher, “we’re engineers because we know how to change the axis of reference”
According to a Chemistry teacher in grad school (who was a chemist): “young lady, with all those questions about ‘what is it good for’, you sound like an engineer!” (my answer “glad you noticed, sir, I am one”)
You know you’re in sales when you admonish people not to buy something from here or there but to go there and here instead. That is if you can’t get it for them yourself.
You know you are a tool and die maker when drinking beer on a Saturday afternoon watching your neighbor butcher the sharpening job on his lawn mower blade using a grinder you can’t stand it anymore. You take it home and use a hand file in 15 minutes get it balanced and looking like new with a better edge than when it was new.