Here is a dialogue from the movie Dumb And Dumber:
1: I wonder what's in this sucker.
2: That thing is worth a fortune! Be careful!
3: It would be nice to know what's in it, though.
1: I've been racking my sack about that.
What does 'Racking my sack' mean here?
Thank you in advance.
This comes as a slightly more emphatic, from a man's point of view, way of saying "racking my brain", which means "to think very hard" ( see to rack)
Probably it has to do with the idea that "a sack" in slang is "a man's scrotum", and probably, just out of pure guess, the wording stands thus 'cause the idea of thinking very hard in this particular context somehow refers to that part of the body.
