I saw this on Futility Closet here. The original source was The Youth’s Companion, Sept. 25, 1879. I think they meant it as a children's riddle, but it's really just a series of bad puns. Like there are any other kind.
Why is this man likely to succeed in life?
Why do we know he has reached middle life?
How does the picture indicate his occupation?
He is bound to XL.
He is over forty.
He is in tent on letters.
Proof positive that some things may change, but bad jokes are forever.