It's a silly idea for a hack. If I can do it for 20 minutes, I can (and will, if necessary) do it for 8 hours; it's getting started with that first 20 minutes that holds me up.

this is also really good advice for working out.

The irony is if you do it for 20 minutes you’ll probably get hooked and go for the next 9 hours - and then that impossible thing will be done :)