In the style of the "You might be a redneck" jokes, I thought I'd compile a nice little list of phrases that, if they ring true for you, might be evidence that you are a Lostie.
a) If everytime you walk by a manhole you wait for a bright light to shoot out of it, you might be a Lostie. b) If you pass by a construction site, and warn all the workers about the electromagnetism they're about to drill into, you might be a Lostie. c) If you're always watching your back to make sure a younger version of your mom doesn't shoot you, you might be a Lostie. d) If you tell every bald guy you meet that he's going to have to die to "bring them back," you might be a Lostie (and you'll probably get arrested) e) If you always look for a frozen donkey wheel inside the zoo's polar bear exhibit, you might be a Lostie. f) If you call every doctor Jack or Doctor Shepherd, you might be a Lostie. g) If you use the phrase "we're not going to Guam, are we?" on more than one family vacation, you might be a Lostie. h) If you have played the lottery with the numbers 4 8 15 16 23 42 more than once, you might be a Lostie. i) If you introduce yourself to strangers as LaFleur, you might be a Lostie (and you definitely need a new nickname) j) If you refer to your annoying next door neighbors as The Others, you might be a Lostie. k) If everytime you pass a construction site, you look for Faraday among the workers, you might be a Lostie. l) If you find yourself asking random people "what hides in the shadow of the statue," you might be a Lostie. m) If you still use that "what did one snowman say to the other" joke, you might be a Lostie. n) If you know a girl named Penelope, and you've told her that Desmond is looking for her, you might be a Lostie (and she'll probably be confused) o) If you've ever gotten a journal as a gift, and then begged the gifter not to kill you later, you might be a Lostie.
I had more, but I can't remember any of them. Please offer up your own if you have any.