A “Memento” Joke

Our friend Snarla just sent in this:

The tachyon leaves.  The bartender says:  “We don’t serve your kind here.”  A tachyon walks into a bar.

This excellent joke (excellent on several levels) is given extra poignancy by the barroom scene in “Memento”, where the waitress, understandably doubting Leonard’s serial amnesia, tests him by slowing drooling -- in full view -- into the tankard she has just drawn for him. -- The next thing you see, he’s sitting at a little table, and gratefully accepts the tankard.   And she, with a pang and sudden pity, withdraws it to get a new one, saying “That one’s dusty.”