Kellett was educated at public schools in south-west England where he gained a reputation as a perfect all-round sportsman, playing on the cricket and rugby teams and also representing them at boxing (oddly, given his subsequent pacifism). He was a strong chess player and his analytic mind led him initially to qualify in accountancy, but he left the profession in favour of physically demanding forestry work in Ennerdale in Cumbria where he began to climb more seriously than on his early forays on the Tors of Dartmoor. With the coming of the second world war Kellett refused to serve on grounds of conscience and was interned for two years. He eventually proposed serving with the forestry on Skye where he could climb on the magnificent Cuillin ridge, but was posted at Torlundy instead. Kellett was by all accounts industrious - born to work the land, in the words of a co-worker - and now he could climb again, too: Torlundy is seven kilometres north of Ben Nevis, the highest mountain in the UK.