Simplify the following text for a Grade 12 native English-speaking person.
Original: Maharishi Mahesh Yogi ( SanskritÂ ' ) , born Mahesh Prasad Varma ( January 12 , 1914 â `` February 5 , 2008 ) developed the Transcendental Meditation technique and was the leader or `` guru '' of the TM movement , varyingly characterised as a `` Neo-Hindu '' new religious movement .
Simplified: Maharishi Mahesh Yogi ( January 12 , 1918 - February 5 , 2008 ) was an Indian guru ( a teacher of spirituality ) . He was most famous for his development of Transcendental Meditation .