The purple gentian is an unassuming wildflower that emerges in the cold November sun. Amenable to harsh conditions, it brightly carries on when other flowers have long since disappeared. Emily Dickinson, the American botanist better known as a poet, wrote admiringly about the gentian—“The frosts were her condition”—and claimed it as a vital emblem of her own late development. In her poems, the gentian proclaims that the late bloomer comes tardily, but shines gloriously in adversity.

For most people, however, there is nothing glorious in having to wait too long for success or in taking on mundane challenges that others overcame long ago. A 30-year-old wobbling unsteadily on a bicycle or floundering in the shallow end of a swimming pool is hardly the ravishing late bloomer Dickins...