Heroism often results as a response to extreme events.
You only really discover the strength of your spine when your back is against the wall.
By bringing together what we know and what we don't know through analogy, metaphorical thinking strikes the spark that ignites discovery.
Aphorisms are literature's hand luggage. Light and compact, they fit easily into the overhead compartment of your brain.
A simile is just a metaphor with the scaffolding still up.
I believe aphorisms are best when first read in the wild, free from the confines of any categories.