Mr Wheeler said he had been kept active and eager to stay in his post by the pupils, their parents and his staff, who he will miss. However, he is glad to be escaping the bureaucracy and government initiatives.
Mr Wheeler said heads had faced workload stresses ever since he took his first headship in 1974 - but the piles of paper were growing ever higher.
"The worst thing is the amount of paperwork teaching staff get bogged down in - a lot of work teachers feel is unnecessary."
It is a far cry from his first job as a 21-year-old teacher. Then a deputy head would come round the staffroom each morning to discuss schedules and pupil issues.
"He would kneel down by the side of each teacher's chair, make notes and plan the timetable on the back of his fag packet," Mr Wheeler said.
Mick Brookes, National Association of Head Teachers' general secretary, said Mr Wheeler had bucked the trend of heads wanting to leave as soon as they could.
"The pressures of the job are such that they opt to damage their pension entitlement rather than stay till their retirement date," he said.
Photograph: Richard Hanson