“What’s the difference between a golf ball and a G-spot?” (joke)

A popular sex joke involves a golf ball:
 
Q: What’s the difference between a golf ball and a G-spot?
A: A man will spend 20 minutes looking for a golf ball.
 
The joke has been cited in print since at least 1996. The time given is usually “20-30 minutes,” but has also been given as “five minutes” and “an hour.”
 
   
Google Groups: alt.tasteless.jokes
Golf Ball & G-Spot
James Gustafson
8/7/96
What’s the difference between a golf ball and a G-spot?
A man will spend 20 minutes looking for a golf ball.
 
Google Groups: rec.sport.golf
Golf ball & G-spot difference?
chi_chi
8/21/96
What is the difference between a golf ball and a G spot?
A man will spend 20 minutes looking for a golf ball!
 
IMDb (The Internet Movie Database)
In the Company of Men (1997)
Quotes
Chad: What’s the difference between a golf ball and a G-spot? I’ll spend twenty minutes looking for a golf ball!
 
Google Books
Sex on the Brain:
The Biological Differences Between Men and Women
By Deborah Blum
New York, NY: Viking
1997
Pg. 234:
What’s the difference between a G-spot and a golf ball? A man will spend 20 minutes looking for the golf ball.
   
Google Books
501 Golf Jokes for (Almost) All Occasions
By Franklin Dohanyos
New York, NY: Barnes & Noble
2001
Pg. 64:
Q: What is the difference between a lost golf ball and the G-spot?
A: A man will spend five minutes looking for the lost golf ball.
 
Google Books
Golfing Wit:
Quips and Quotes for the Golf-Obsessed
By Aubrey Malone
Chichester, West Sussex: Summersdale Publishers Ltd
2007
Pg. 222:
What’s the difference between a G-spot and a golf ball? Men will spend more than ten minutes looking for a golf ball.
Anon
 
Google Books
Jokes for Blokes:
The Ultimate Book of Jokes not Suitable for Mixed Company
By Llewellyn Dowd and Phil McCracken
New York, NY: Ebury Press
2011
Pg. 55:
What’s the difference between a golf ball and a G’spot? A man will spend 20 or 30 minutes looking for a golf ball.