Your frame is old when:

young guys say, "wow, that's a classic! They don't make'em like that any more...what do they get for them on e-bay?"

you've replaced all the original moving parts (not just cogsets and chains, I mean headsets, bb's, re-built wheelsets) on your frame at least three times at a minimum.

riders of your generation say, " I remember those...can you still find parts for your drivetrain?"

So no, 3k is nothing. My current frame probably has 30k in it and at least 8 crashes that I can remember. It matches all the critieria above.