Narasimhaiah was born in Hossur, a village near Gauribidanur in Karnataka, India. His father was a village school teacher, and mother, a labourer. He had a younger sister. Having no formal school in his village, he attended the Government School in Gauribidanur, the nearest town. He completed his elementary education in the primary school, which had no further studies beyond eighth standard. He stopped school for a year. His school headmaster M.S. Narayana Raio, who had just been transferred to the National High School, Basavanagudi in Bangalore, invited and helped him get admission in his new school. Without money, he went on foot to Bangalore (about 85 km), taking two days to arrive, and joined the school in 1935. He stayed with his headmaster for six months, until he could get allotment in the school hostel, the Poor Boys' Home, as he called it. He met with Mahatma Gandhi when the latter visited the National High School in 1936. His teacher selected him to be the interpreter of Gandhi's Hindi speech into Kannada. From this moment on, his life was entirely influenced by Gandhi's views and lifestyle, including wearing "khadi" throughout his life. He went on to Central College of Bangalore studying for his B.Sc. During his final year in 1942, Gandhi launched the Quit India movement to end British rule. He gave up his degree to join the movement, the event which he described as "the most momentous decision in my life." The consequence of his decision was his imprisonment for nearly nine months, in different jails, in Yerwada Central Jail, in Mysore jail and in the Central Jail in Bangalore. Comparing his Central College hostel and the Central Jail, he remarked that he found "no difference" between the two as both provided him "free boarding and lodging." After a year he completed his bachelor's degree, B.Sc. with physics honours. He earned his MSc in physics with first class from the Central College in 1946. The same year he started his academic career as a lecturer at the National College, Bangalore.