Why you (or anyone) shouldn't think about how many hours you work.
The more you think about hours, the less you think about results. Success hinges on a single-minded focus on results. Therefore, you shouldn't think about hours at all. (How's that for a syllogism.)
Corollary: telecommuting. Telecommuting is good for any organization. It involves thinking about hours less. That's good.
Corollary: goals. If you stop thinking about hours, you'll find out really fast if you have any goals. If managers suddenly panic because they don't know whether anyone is doing any work, then your organization has no goals. That's a reason to go to telecommuting / no hours immediately – you need goals in a hurry.