wolf

I haven't heard the phrase before, but it probably means something like that. More accurately, it probably means he got himself into trouble--i.e. he could have avoided it if he had been more careful, but he wasn't more careful and thus got into trouble.

There are a lot of sleepers in English idioms.

China is often referred to as "the sleeping giant" and we are constantly reminded that she is about to awake.

Then there is "Let sleeping dogs lie." meaning "Leave well enough alone." or the present condition is acceptable, don't attempt to change anything.

I am not familiar with the wolf one you refer to.

Joe

My favorite one is (of course!) the Hogwarts motto: "Never wake a sleeping dragon."