rocket surgeon

Blend of rocket scientist +‎ brain surgeon, as both are commonly used in such phrases as "you don't have to be a rocket scientist to understand it".

rocket surgeon (plural rocket surgeons)

1. (humorous) Synonym of rocket scientist (“someone qualified to understand or handle that which is overly complex, detailed or confusing”)
   • 2012, Chris Vander Mey, “How to measure greatness”, in Shipping Greatness, O'Reilly Media, →ISBN, page 89:

     At this point you may be thinking, “I know all about goals. I know to make them S.M.A.R.T.” What's S.M.A.R.T? Some rocket surgeon a while back came up with the notion that goals should be specific, measurable, attainable, reasonable, and time-based.

• rocket surgery