“Teachers who take class attendance are absent-minded”

A school pun about teachers taking attendance is:
 
“Teachers who take class attendance are absent-minded.”
 
The jocular line has been cited in print since at least 2004.
 
 
Google Groups: alt.humor.puns
Kids Puns of the Weak 06-08-04
Stan Kegel
6/8/04
(...)
Teachers who take class attendance are absent-minded. (Pun of the Day)
 
Google Groups: alt.humor.puns
Kids Puns of the Weak 02-08-05
Stan Kegel
2/8/05
(...)
Teachers who take class attendance are absent-minded. (Tony Thoennes)
 
Google Groups: alt.x.y
Teachers
~> Bob <~

5/3/07
Teachers who take class attendance are absent-minded.
 
Twitter
Alan S Harrell
‏@ashtexas
Teachers who take class attendance are absent-minded.
3:53 PM - 10 Feb 2010
 
Twitter
Baptist-City.com
‏@BaptistCity
Teachers who take class attendance are absent-minded.
12:08 PM - 3 Nov 2010
 
Google Books
Bad Science Jokes:
Jokes For Alkynes Of Scientists
By Melissa Miller
Lulu Publishing (Lulu.com)
2016
Pg. 111:
Teachers who take class attendance are absent-minded.
 
Twitter
Chase Superman Duffy
‏@SupermanDuffy
JUST FOR LAUGHS: Teachers who take class attendance are absent-minded. #edchat #BellyLaughDay
12:00 PM - 24 Jan 2016