To wrap your head around something is to finally take in an idea that resists you. Wrap your head around the scale of it.
It is the American form of the same idea and is now common everywhere. It is used most for things that are true and hard to feel, like very large numbers.
1phrasewrap your head aroundTo finally take in an idea that resists you.
“Nobody can really wrap your head around a billion of anything.”
wrap your head around is a phrase.
Practised in Thinking & Memory