Kidner, in The Message of Ecclesiastes (Bible Speaks Today),  nails the spirit in which Ecclesiastes 3:11 was written:

We are like the desperately near-sighted, inching their way along some great tapestry or fresco in the attempt to take it in. We see enough to recognize something of its quality, but the grand design escapes us, for we can never stand back far enough to view it as its Creator does, whole and entire, from the beginning to the end.

Tragic yet beautiful.