That's disheartening. Fortunately I've not personally experienced that. Everyone I've known who has departed this garbage scow has never looked back.
The sad thing for anyone who does return, is that the company isn't going to compensate them for their years of experience, they're simply going to say "hello Mr./Ms. NEWHIRE - welcome to FedEx!" They will, however, expect yeoman's performance from them right out of the starting gate.