The twenty-first Book in the Bible is Ecclesiastes. The word Ecclesiastes means "a speaker at an assembly". There is only one speaker in the book - The Teacher. Ecclesiastes is the sharing of one man's search for satisfaction in life, in which we discover that without God there is no meaning to be found. The Teacher wants to spare his readers the harsh lessons which he has himself learned.
Ecclesiastes 1:18
"For in much wisdom is much grief: and he that increaseth knowledge increaseth sorrow"