bog·gle 
/ˈbɑ:gəl/ verb
bog·gles; bog·gled; bog·gling /ˈbɑ:gəl/ verb informal 1 [no obj] : to be unable to think clearly : to be amazed or overwhelmed
▪ The mind boggles at what he has accomplished. = When I think of what he has accomplished, my mind boggles. [=I am amazed by what he has accomplished] 2 [+ obj] : to make (the mind) unable to think clearly : to amaze or overwhelm (the mind)
▪ It boggles the mind to think of what he has accomplished. = His accomplishments boggle my mind. — see also mind-boggling
▪ The mind boggles at what he has accomplished. = When I think of what he has accomplished, my mind boggles. [=I am amazed by what he has accomplished]
▪ It boggles the mind to think of what he has accomplished. = His accomplishments boggle my mind. — see also mind-boggling
