I think the theory is that once you've fully slept off your sleep debt (which I've heard can be up to 40 hours) you are no longer able to sleep much more than your natural sleep requirement, bored or not.
Very interesting, do you have any sources on this? If I forget to set my alarm I can easily sleep for 14-16 hours before I wake, any day of the week. If one possible solution to this is to go on a total sleeping binge for a week or so I'd be thrilled!
Interesting. I can sleep for 12 hours several nights in a row.