Some harder-core smokers (if there is such a thing) and/or foolish young people will get a tattoo of the number "13" - the 13th letter of the alphabet being "m" for "marijuana". As in Pretty Fly for a White Guy by Offspring - "Now he's getting a tattoo yeah, he's getting ink done. He asks for a 13, but they drew a 31." This is the sort of logic stoners use, and probably seems more or less clever depending on what you're smoking at the time. Of course, there are plenty of other people who get a 13 tattooed on them: members of the Mexican Mafia, tattoo artists who have been pro's for 13 years, guys who are trying to remember what 6+7 equals, etc.
Not that 13 ever had a lot of significance w/r/t weed for me, personally - it's always been one of my "lucky" numbers, or at least the default when someone asks me to think of a number between 1 and 20 (or higher). Which once you get out of grade school doesn't happen very much... I guess for the 13 to make sense, I would've had to smoke at 4:20 on that day, which I'm pretty sure I didn't.
Part of me thinks that keeping track makes a bigger deal of quitting than it needs to be. But the other part thinks it's probably good to have SOME sense of how long it's been for measurement purposes. These are probably the same parts of me that respectively like the healthy/frosted sides of Shredded Wheat. But I digest...
I will say that keeping track is becoming less important as time goes on - like birthdays, I guess. Which is good - seems to me that it makes the whole affair less hysterical in general. And there's always been enough hysteria attached to the mighty herb:

So, in summary: yippee-sh!t, it's been a month since I quit. Yay, me.
