In Young v. R.R., 266 N.C. 458, 466, 146 S.E.2d 441, 446 (1966), this Court explained the collateral source rule. According to this rule a plaintiff's recovery may not be reduced because a source collateral to the defendant, such as "a beneficial society," the plaintiff's family or employer, or an insurance company, paid the plaintiff's expenses. Rather, an injured plaintiff is entitled to recovery "'. . . for reasonable medical, hospital, or nursing services rendered him, whether these are rendered him gratuitously or paid for by his employer.'"