There are certainly a lot of people getting grad degrees that shouldn't (not saying you Dopple). Actually, as a teacher, you are much better off getting a MA and not a PhD, which will overqualify youfor a number of jobs. You don't need a PhD to teach at a college, plenty of MA/MSc faculty.
Maybe we should just put degrees inside fortune cookies...
Second thoughts can generally be amended with judicious action; injudicious actions can seldom be recovered with second thoughts.
--Cyteen by C.J.Cherryh