get your head round something

get (one's) head around (something)

To understand something that is challenging or confusing. It took a while, but I've finally gotten my head around this chapter in my calculus textbook. Wait, you two are dating now? It's going to take a little while for me to get my head around that!
See also: around, get, head
Farlex Dictionary of Idioms.

get your head round (or around) something

understand or come to terms with something. informal
See also: get, head, round, something
Farlex Partner Idioms Dictionary

get your ˈhead round something

(British English, informal) understand something difficult, often with a lot of effort: The plan is so complicated — I’m still trying to get my head round it.
See also: get, head, round, something
Farlex Partner Idioms Dictionary
See also:
  • get (one's) head around (something)
  • get your head around something
  • get (one's) arms around (something)
  • get (one's) mind around (something)
  • a horse of another
  • a horse of another colour
  • horse of a different color
  • horse of a different color, a
  • horse of another color
  • horse of another/different color, a