My chat lingo dates me

I was informed today by my young apprentice here in the London office, who is about 24, than my use of "tyvm" in chat flags me as a long time internet user. The tone she used to inform me of this was tinged with tragedy and astonishment. The tone said, "Wow, you're really old."

My IM style dates me. I didn't know this was possible, of course I also just started to use Facebook in the last 2 months, so I know I'm behind the curve.