Truth is stranger than fiction.

Lord Byron wrote in Don Juan,
“’Tis strange – but true; for truth is always strange:
Stranger than fiction.”

According to the Oxford Dictionary of Phrase, Saying and Quotation, the first sentence in this post is derived from Byron’s version of it.

File:Byron 1824.jpg  Photo Credit Wikimedia Commons

Doesn’t sense involve distinguishing between fact and fiction?

Keep your wits about you!
Nowadays this might be advice to be streetwise.

Use some common sense.
As a child this expression used to baffle me.  It is the sort of sense everyone should have.

You haven’t the sense you were born with.
Perhaps I was told this too many times!

Where there’s no sense there’s no feeling.
Sense (as in sensation) and feeling are synonyms.

Don’t be silly!
Did you know silly did not originally mean rather daft? It meant blessed or happy.

To do something without thinking is not always the best plan.

Neither rhyme nor reason sounds to me as if poetic licence may allow for a deviation from fact; it is usually said when something unreasonable has happened.

Nicolas Boileau in L’Art poétique is translated as saying,  “Whether one is treating a light or exalted subject, let the sense and the rhyme always agree”.  (The Penguin Dictionary of Quotations)

Some people may be wise beyond their years, although others would argue that you can’t put an old head on young shoulders (an expression I used before).

It’s easy to be wise after the event is a saying about hindsight.

See the light and
Has the penny dropped? are expressions about understanding.  The former is often used about a change in outlook, such as a conversion.  The latter is more usually concerning mundane matters.

She sees things in black and white.

Something is either right or wrong, no shades of greyAfter all the publicity surrounding a famous title, which includes those words, I recommend Shades of Grey by Jasper Fforde.

Down-to-earth means practical.

Who on earth would…

Whatever were you thinking of?

Whatever possessed you to do that?
are three ways of expressing disbelief and shock at something, which has been done.

“Are you a wise virgin?” was once asked of a young man, who had not been brought up to know the Bible.  He was nonplussed, to say the least.

The story or parable told by Jesus can be found in Matthew Chapter 25 verses 1-13.  If you are not familiar with it, I hope you will be curious enough to click on the link or look it up.  (Free Bibles are available for the Kindle!)