“Welcome back to invisibility class. It’s pretty disappointing to see so many of you here”

A teacher often welcomes students back to class. A joke was posted on Twitter by JB 4 Realz on May 10, 2019:
     
“Welcome back to invisibility class. It’s pretty disappointing to see so many of you here.”
 
A similar joke has been told by American stand-up comedian Emo Philips:
 
“I was walking through college and my camouflage teacher said I haven’t seen you in class.”
     
   
Twitter
JB 4 Realz
@JB4Realz
welcome back to invisibility class.
it’s pretty disappointing to see so many of you here.
5:03 PM - 10 May 2019
 
Reddit—Jokes
Posted by u/JustSomeGuy_Idk May 13, 2019
Welcome to invisibility class.
I’m pretty disappointed to see so many of you.
 
Reddit—3amjokes
Posted by u/Pulsse May 13, 2019
Welcome everyone, to invisibility class
Pretty disappointed to see so many of you here
   
Twitter
El Diablo Says: #WeAreThePatriots
@theonlyElDiablo
Welcome to the first annual invisibility conference. I must say I’m disappointed to see so many of you here.
12:56 PM - 13 May 2019
   
Twitter
Mr. Drinks On Me
@Mr_DrinksOnMe
Welcome to invisibility class. I’m pretty disappointed to see so many of you.
5:47 PM - 13 May 2019
   
Facebook
Adzema Pharmacy
May 13, 2019·
Monday-The professor said “Welcome to invisibility class. I’m disappointed to see so many of you!”