“ Every man has had one horrible adventure: as a hidden untimely birth he had not been, as infants that never see the light. Men spoke much in my boyhood of restricted or ruined men of genius: and it was common to say that many a man was a Great Might-Have-Been. To me it is a more solid and startling fact that any man in the street is a Great Might-Not-Have-Been. ”
 G. K. Chesterton, Orthodoxy (1908). copy citation

add

“It is a good exercise, in empty or ugly hours of the day, to look at anything, the coal-scuttle or the book-case, and think how happy one could be to have brought it out of the sinking ship on to the solitary island. But it is a better exercise still to remember how all things have had this hair-breadth escape: everything has been saved from a wreck. Every man has had one horrible adventure: as a hidden untimely birth he had not been, as infants that never see the light. Men spoke much in my boyhood of restricted or ruined men of genius: and it was common to say that many a man was a Great Might-Have-Been. To me it is a more solid and startling fact that any man in the street is a Great Might-Not-Have-Been. But I really felt (the fancy may seem foolish) as if all the order and number of things were the romantic remnant of Crusoe's ship. That there are two sexes and one sun, was like the fact that there were two guns and one axe.” source