The stresses MMY talks about are akin to the 7 deadly sins which prevent the serpent fire to rise up the spine. Until a modicum of Self-Control is obtained the ultimate Reality of life will remain a mystery to you.
Initially we coddle our lower nature, (lust, anger, greed/gluttony) but after starting TM, these "sleeping elephants" start becoming a recognizable obstacle to us on our path, and must be dealt with once and for all, this is ARMAGEDDON! The Bhagavad Gita is about this Armageddon between the lower nature/vices (Kurus), and the higher nature/virtues (Pandavas). Some day we all must fight this 'war', and some day we all must win it!! Ohhhh, Enjoy! (A few things MMY didn't tell you)!