I haven't worked since 1988. Beat that.
Wait, what was the question again?
The reason why "everyone says they make 6 figures" is those people are the ones who are proud of their income, and rightly so, so they post about it. Not that everyone who makes that much does post it, but I'm sure a lot of people who do make it, have posted it in some kind of fashion. Why not.
I've never understood the whole "OMG don't mention your salary!" thing. No big deal, especially if it pertains to the subjexct at hand. "Hey I'm getting s raise! It's 7.865% above the 3.115% I got last year, omg so that makes it 75th percentile of my company, which means I'm making 'average + XX' I'm so happy!"
WTF? I just got a raise from 55k to 63k woohoo! what's the big deal?