“If you’re drinking to forget, please pay in advance”

“If you’re drinking to forget, please pay in advance” is a jocular sign in many drinking establishments. “If You’re Drinking to Forget, Please Pay in Advance” has been cited in print since at least 1958.
 
“When I told the doctor about my loss of memory, he made me pay in advance” is a related joke.
 
 
24 December 1958, The Morning Herald (Uniontown, PA),  “Dream Street” by Robert Sylvester, pg. 2, col. 4:
Sign over the bar at the Bird ‘n’ Glass: “If You’re Drinking to Forget, Please Pay in Advance.”
 
14 May 1960, Boston (MA) Daily Record, “Maverick Runnels Leading Stampede” by John Gillooly, pg. 26, col. 1:
“If You’re Drinking to Forget, Please Pay in Advance” urges a sign in a local saloon, according to a friend who loiters there,
 
8 September 1960, Chicago (IL) Tribune, pg. W16:
I suggest this sign for clubs and taverns: “If you re drinking to forget, please pay in advance.”
 
Google News Archive
30 September 1962, Sarasota (FL) Journal, Walter Winchell column, pg. 2, col. 4:
Poster over a 3rd Avenue Bar: “If You’re Drinking To Forget Kindly Pay In Advance.”
   
Google Books
Humor in Advertising, and How to Make it Pay
By Don Herold
New York, NY: McGraw-Hill
1963
Pg. 191:
And a poster over the mirror in a Third Avenue bar: “If You’re Drinking To Forget, Kindly Pay in Advance.”
 
New York (NY) Times
Everything’s Relative Around Here
By LEANNE SHEAR
Published: May 29, 2009
(...)
Sure, some South Buffalonians sit around, drowning their discomfort in vats of beer — and appropriately, a sign above the bar admonishes, “If you’re drinking to forget, pay in advance.”
 
Google Books
The Skeleton Box:
A Starvation Lake Mystery
By Bryan Gruley
New York, NY: Touchstone
2012
Pg. 67:
Beneath the TV hung a sign that said “If you’re drinking to forget, please pay in advance.”