have one's work cut out for one
Face a difficult task, as in This is a very large house to manage, so I have my work cut out for me. This expression alludes to cloth cut out to make a garment. [c. 1600]
The American Heritage® Idioms Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company.