I was reading a book and I found this odd (to me) sentence:

"You know better than to go riding off when a storm's approaching"

I was taught that "better than" is used to compare two things:

A is better than B.

But in this sentence, I have no clue what's being compared.

Awful awful sentence. Is this a common/natural expression?

Question

I was reading a book and I found this odd (to me) sentence:

"You know better than to go riding off when a storm's approaching"

I was taught that "better than" is used to compare two things:

A is better than B.

But in this sentence, I have no clue what's being compared.

Awful awful sentence. Is this a common/natural expression?

Answer

Common, natural and correct 🙂

The person being addressed knows they shouldn't have gone riding off in that situation.
It's comparing what they did with what they know.