Bummed that I missed this discussion when it was current. (just noticed the big warning about bumping a necro-thread

)
I keep a very strict round count on all of my firearms, and yes-- even the ones that aren't new when I get them. (which is dang near most all of them because I prefer used guns!)
I could sit here & try to convince someone how "important" it is to do so, but I don't believe that. Frankly, I just
enjoy doing it. It's all for me, really. I can keep track of how much exercise each one has gotten, and it's fun for me to watch the round counts climb on some of them. It's also a good reminder in the log when one hasn't gotten much action.
On a range day, I have one slip of paper that tallies up each participant and it all gets entered on the excel spreadsheet soon after.
I really enjoy keeping such counts. Some folks say their carry gun "has had thousands of rounds through it" and it sounds made up on the fly, often because it is exactly that. It's a clouded memory, some hopefulness, some forgetfulness and a smidge of BS tossed in for good measure.
My log tells me that my EDC has 4,428 shots through it, and it also says I haven't shot it since June 2nd. That means it's due for some exercise!

And there's nothing corrupting THAT number... that number is fact.