"In any case, my point was -- am I making myself prone to commiting errors because I am always depending upon the perl -w switch to complain. Its like constantly depending on the calculator and hence, losing the ability to compute basic math quickly in one's head. "

You're confusing diagnosing errors with committing errors . Using -w all the time might reduce your ability to quickly FIND an error, but it won't reduce your ability to PREVENT an error. Given that -w exists, why make life more painful? Find the errors and move on.