They have never licked a postage stamp. (Class of 2019, #3)
Maybe the Beloit College Mindset List can use this item again for the class of 2037 List because the year that the U.S. Post Office announced its plan to discontinue lick-and-stick stamps is 2015.
According to Linn’s Stamp News & Insight, the Postal Service has been experimenting with self-adhesive stamps since 1974 (a couple decades before the birth of the class of 2019) and most stamps have been self-adhesive starting in 2002 so it’s unclear what stamp-related event attracted the attention to the Mindset List gang.
If you have a preference for lickable stamps, they will be available from your local Post Office while supplies last.