“Mike”, as he was known, was born on the 1st December 1896 – the 7th child of Alfred and Bessie Cobbold, of Bramford House, Ship Lane. His two older brothers also served in the war: 2nd Lt Rowland Townshend Cobbold, Royal Artillery (killed in action 25th September 1915) and Commander Sterling Neville Cobbold, RN (see below).
His biography and photograph from the Cobbold Family History Trust website are reproduced here:

“Mike’s prep school was St Ronans in Worthing, Sussex where records show that he was in the football team for three years, 1908, ’09 and ’10 and in the cricket team for two years, 1909 and 1910. He and his brother S N Cobbold (#401 on the family tree) (there was only 13 months between them) were at the same school and S N C played in the 1907 football team and the 1908 cricket team. As if that wasn’t enough the brothers’ third cousin, F R C Cobbold (#334) was there too, playing football in 1907 and ’08 and cricket in 1906, ’07 and ’08.”
Anthony Cobbold 2015
https://family-tree.cobboldfht.com/biographies/403/alfred-michael-mike-gordon-cobbold

Nothing has been found about his time between attending St Ronan’s School and being commissioned into the Royal Engineers on the 2nd November 1918. However, the 1921 Census records him as a boarder in York working as a Temporary Foreman for the North East Railways, Locomotive Department.
He appears to have followed in his late brother’s footsteps (Rowland) and gone to work in Argentina. Passenger records show him travelling back to the UK from Buenos Aires in the 1930’s and 40’s – his occupation is given as an Engineer.
He had married in 1944 and died in 1971 in Buenos Aires.