You've seen the optical illusion asking whether it's two faces or a vase.  Actually, it's a bottle, and it's a drinking problem.

That feeling of being a pencil-like fairy in jar, not having been told what would happen tomorrow.  From Fairy Grammar by John Harold Carpenter, 1920.

From The Cats' Arabian Nights by Abby Morton Diaz, 1881.

From the Naval Academy's 1905 yearbook.

From the Wizardry III: Legacy of Llylgamyn strategy handbook.

From George Fox's 1974 yearbook.

From Salem's 1977 yearbook. 

From Nebelspalter, 1914.

From Nebelspalter, 1909.

From the rare (over $900 on Amazon) Ghosts and Spirits of Many Lands by Freya Littledale and illustrated by Stefan Martin.

How to decline if offered Hitler in a champagne glass, even if all your friends are taking freebies: Keep it clear and simple (just say "no"); don't offer an explanation (you don't owe them one).

Headline from The Martlet, 1972.