Mind Blowing vs. Mind Boggling

Solution 1:

In my experience 'mind-blowing' is an Americanism, but is creeping overseas. 'Mind-boggling' is used more by the British, but they usually say 'boggles the mind!' The two phrases have almost the same meaning. 'Mind-blowing' refers to a highly stimulating event or experience, such that it overwhelms the senses. 'Mind-boggling' or '(it) boggles the mind' is usually used to refer to an overly complicated, confusing, self-contradictory policy or unfathomable attitude, situation or position (usually taken by an administrative organ of government). Bureaucracy is usually loaded with 'mind-boggling' regulations.

Solution 2:

I would agree with both of the other answers.

The evolution of the two phrases is rather interesting. The phrase "the mind boggles" goes back to about 1915, with "mind-boggling" as an occasional adjectival form. Note that "mind-blowing" does not appear to have been used at all. The use of "mind-boggling" from 1901 to 1907 is one which I have not been able to track down.

Then we reach the sixties, and the phrase "mind-blowing". Well, first there was "blew my/his/her mind". (Note that the 1940s/1950s usage is actually an artifact of how n-gram works, and is not accurate.)

However, "mind-boggling" is the big winner, with "mind-blowing" seeming to ride along as an alternative.