The reddit alien fighting Germans in the trenches

A dog is afraid of the dark, and the sun is going down.

An hourglass halfway between 0 and 60, on a stage.

The jabberwock, with eyes of flame, came whiffling through the tulgey wood, and burbled as it came.

The volcano proclaimed that the couple were to wed the following day, and there was much rejoicing. Until everyone burned to death.

Why is six afraid of seven?