Boggle (one's)/the mind
Used to describe being difficult to understand because of their abnormality or complexity.
Nancy is a good student but sometimes her strange behaviors boggle my mind.
Women's mood is something that boggles my mind. I found it really hard to understand them.
The size of the universe is still a mystery. To figure out its real size really boggles scientists' minds.
Despite being explained many times, the way to solve this algorithm still boggles my mind.
To greatly surprise, shock, or confuse someone
To be astonished by the occurrence of sudden situations
To surprise, astound, or disturb
It's mostly used in the present tense.
A problem or difficult circumstance
I'm short-sighted, so forgetting my glasses is a real hair in the butter for my sight.