I’ve just come across this site of letters, thanks to a Simon Singh tweet. This was the second letter I read. The site explains enough, and the letter is one of those pieces that you wished you’d written yourself. So I’ll say no more. Just read:
On the Meaning of Life by H. L. Mencken.
Ramblings 
an alternative source
https://harolddlevine.blogspot.com/2012/02/hl-mencken-on-meaning-of-life.html?m=1