Early on in my career I knew I wanted to focus on tax. So, in addition to becoming a CPA, I also obtained a Master's in Taxation. Not something I mention at parties (unless I am trying to clear everyone out), but it does mean I know a lot about tax laws.
The CPA license is vital in my world. It separates us from unlicensed and unregulated tax preparers that can sometimes develop some bad practices. It also requires us to take 40 hours of continuing education each year.
Fun fact about having the Master's degree. It qualifies me to teach at a lot of universities. In fact, I was an adjunct professor for 12 years teaching mostly tax courses.