Luck? well maybe. Each chip is different and they don’t have the same overclocking potential.
I wouldn’t attribute all the systems I’ve overclocked to luck though.
I’d attribute my experiences to good airflow, decent case, thermal paste, etc…more than luck or anything else.
Good for you, your P2 might live forever, but it’s not a P4. Processors can and do die from overclocking, just because it didn’t happen to you, doesn’t mean they don’t. 
See my sig.
My P4 2.4C GHz is overclocked pretty close to it’s limit. 3.5GHz is pretty much the limit on air, and thats only if you have a decent case with good airflow/quality thermal paste.
My Barton 2500+ is pretty much at it’s limit on air. I think you’ll find that 2.2GHz is pretty much the limit that 90-95% of overclockers reach on air for this CPU.
Both systems have been overclocked since Spring 2003 and are running perfectly fine. I have no doubt that either systems can still live for at least 5 more years in their current state.
No short term effects has been noticed, and longterm effects are still to be determined.
Oh and I have no intent of using liquid nitrogen or water cooling setup.