If you need to know how to be funny, besides telling a couple of corny jokes, there are some well tested methods you can use to get a few laughs.
It is as if life starts when you turn 40, and simply improves day by day!

They are not less than us; we are ignorant to expect that.

Don't simply come out of the blue with a tag line. Buy him a book loaded with jokes or simply an amusing book. Comics and funny books can be found in every range.