I'm with Rich and Fazc.
I don't think mind-muscle connection is a myth as much as it is simply a misunderstood concept. Having solid form, working the desired range of motion, and feeling the target muscles contract and work just seems obvious to me.
For me, an example was the difference between BB and DB bench. By using DBs, I can really feel my chest working more (along with the normal tricep and delt feelings). I never felt that with BB benching, where my arms and delts did more of the work.
Complication makes it easy to explain failure.