As to that long opening sentence, let’s just quote it for good measure:

In my old tree-climbing days - a long time ago now, many many years have passed since then, I was just over three foot four, my shoe size was a child’s ten, and I was so light I could fly - no, that’s an exaggeration, I really could fly - or nearly, or let’s say it was within my power to fly, if only I’d put my mind to it and tried as hard as I could…I can clearly remember the time I all but flew, it was on an autumn day in my first year at school, and I was just on my way home from school, and there was such a strong wind blowing that without even spreading my arms I could lean into it at a sharp angle like a ski-jumper, or even more, without falling over…and when I ran down the grassy slopes of School Hill into the wind - because the school was on a little hill outside the village - and I pushed off just a little way with my feet and spread my arms, then the wind lifted me up, and I could quite easily jump five or ten feet up in the air and twenty or thirty over the ground - or maybe not quite as high and as far, but what’s it matter! - anyway, I was almost flying, and if I’d just unbuttoned my coat then and held my coat tails in both hands and spread them like wings, why, then the wind would have picked me up altogether, and I would have soared off School Hill with the greatest of ease, across the valley down to the woods, and then across the woods down to the lake where our house stood, and there, to the boundless astonishment of my father, my mother, my brother and my sister, all of whom were far too old and heavy to fly, I would have executed a stylish loop over the garden and swung out over the lake, going almost to the opposite shore before finally leisurely letting myself be wafted back, and still be home in time for lunch.