I worked for a law firm (now one of my clients) for 11 years and left when new partners chiseled away our benefits and pay and when more and more was expected for less and less. I did ALL the bookkeeping. I was the only one who knew the bookkeeping software. But, no one was hired before I left. The managing partner said that the secretaries could surely keep up until they hired a bookkeeper. One week later, the senior partner (husband to the managing partner) called and begged me to come back part-time. He said the firm was "going down the drain" without me. I started working evenings and weekends for double the hourly wage that I made before leaving. Eventually, someone was hired and I trained her but she couldn't keep up with the work. I continued working weekends until they hired a second bookkeeper. Two people to replace me. A year later, an attorney in town told me that that the senior partner told her that one of the biggest mistakes he made in his professional life was letting me leave without trying to do whatever it took to keep me.
Deb and I had the same experience. I'm sure she's appreciated more now than she was when she was working. My revenge is that I now work as an independent contractor for that firm and raise my hourly rate whenever the hell I want to. In fact, I just did!