The argument was correct; the data were absolutely wrong.

From Churchill: The Power of Words edited by Martin Gilbert. Subtitled His remarkable life recounted through his writings and speeches.

From My Early Life by Winston Churchill.

My aunt, Lady Wimborne, had lent us her comfortable estate at Bournemouth for the winter. Forty or fifty acres of pine forest descended by sandy undulations terminating in cliffs to the smooth beach of the English Channel. It was a small, wild place and through the middle there fell to the sea level a deep cleft called a ‘chine’. Across this ‘chine’ a rustic bridge nearly 50 yards long had been thrown. I was just 18 and on my holidays. My younger brother aged 12 and a cousin aged 14 proposed to chase me. After I had been hunted for twenty minutes and was rather short of breath, I decided to cross the bridge. Arrived at its centre I saw to my consternation that the pursuers had divided their forces. One stood at each end of the bridge; capture seemed certain. But in a flash there came across me a great project. The chine which the bridge spanned was full of young fir trees.

Their slender tops reached to the level of the footway. ‘Would it not’ I asked myself ‘be possible to leap on to one of them and slip down the pole-like stem, breaking off each tier of branches as one descended, until the fall was broken?’ I looked at it. I computed it. I meditated. Meanwhile I climbed over the balustrade. My young pursuers stood wonder-struck at either end of the bridge. To plunge or not to plunge, that was the question! In a second I had plunged, throwing out my arms to embrace the summit of the fir tree. The argument was correct; the data were absolutely wrong. It was three days before I regained consciousness and more than three months before I crawled from my bed.

The measured fall was 29 feet on to hard ground. But no doubt the branches helped. My mother, summoned by the alarming message of the children, ‘He jumped over the bridge and he won’t speak to us,’ hurried down with energetic aid and inopportune brandy. It was an axiom with my parents that in serious accident or illness the highest medical aid should be invoked, regardless of cost. Eminent specialists stood about my bed.

Later on when I could understand again, I was shocked and also flattered to hear of the enormous fees they had been paid. My father travelled over at full express from Dublin where he had been spending his Christmas at one of old Lord Fitzgibbon’s once-celebrated parties. He brought the greatest of London surgeons with him. I had among other injuries a ruptured kidney. It is to the surgeon’s art and to my own pronounced will-to-live that the reader is indebted for this story. But for a year I looked at life round a corner.

Two lines in there:

The argument was correct; the data were absolutely wrong.

and

But for a year I looked at life round a corner.