Looking closely at proverbs and clichés is a great way of seeing how ideas are embedded in culture. More than that, they can also show us how behavioural principles have been intuitively understood by everyone for centuries.

It goes without saying.  This alludes to system one thinking – we instinctively interpret the world around us, most of the time never stopping to articulate what we’re thinking because it’s below the level of consciousness – or too obvious to have to say out loud.
Glass half full.  The lens through which we see the world colours our impressions of it. Otherwise known as framing.

Better the devil you know.  The status quo bias recognises that we prefer to keep doing what we’re doing rather than to change. It’s obvious on a human level but it’s quickly forgotten in business where most companies and briefs talk about reasons to switch – and fail to recognise that most people are actually looking at reasons not to.
Behavioural science is a no-brainer (forgive the pun) when you think of it like this. Our job is to be minutely observant to figures of speech and clichés and allow them to reveal the behavioural principles that underpin them.