No, but I can tell you the only thing that works for me: I have to have a problem that I really, really want to solve. It's not necessarily a problem that I hav

No, but I can tell you the only thing that works for me: I have to have a problem that I really, really want to solve. It's not necessarily a problem that I have, it could be -- and often is -- a problem that other people have. The more people have it, the more I want to solve it. If I've got something like that to focus on, then I'm less likely to lose interest halfway into it.