Nothing lasts forever, and so it is with gage accuracy and repeatability. Drop them enough, subject them to the rigors of manufacturing plants or mar their measuring surfaces from abrasive contact and sooner or later gages will need to be re-calibrated. Most quality-conscious machinists and inspectors will agree on this, but how gages get calibrated, who calibrates them and where calibration is performed is an important topic.
Aside from the obvious quality pitfalls of using gages that are not accurate, avoiding calibration can be costly in other ways. Without a proper calibration schedule, companies can face decreased productivity and the loss of business contracts because of the lack of measuring compliance or certification.