A: Now that your kids are back to school, do you have any plans for yourself?

B: I think I’m going to take a page out of your book and start going for a run in the morning.

Note: This idiom means “to do something in the way someone else would do it; to behave or act like someone else.” The meaning is quite obvious. The book is a metaphor for “example” - so someone’s book is like a manual for living and taking a page out of it is to copy after that person’s example. People also use “to take a leaf out of someone’s book,” meaning the same. For example: You’re working too hard. Take a leaf from my book and relax!