bog ‧ gle /ˈbɒɡ ə l $ ˈbɑː-/ BrE AmE verb
[ Date: 1500-1600 ; Origin: Perhaps from bogle ; ⇨ ↑ bogey ]
the/your mind boggles, ( also something makes the/your mind boggle , something boggles the/your mind ) informal if your mind boggles when you think of something, it is difficult for you to imagine or accept it:
The sheer amount of data makes the mind boggle.
the/your mind boggles, at
My mind boggles at the amount of work still to do.