you've lost me
I can't follow what you're saying, I'm puzzled or bewildered. For example, Please explain it again; you've lost me. This turn of phrase transfers losing one's way to discourse. [c. 1960]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.