I can't remember the last time I left work at a reasonable hour. It's usually way past 8pm as I close down my computer for the day and head out into the evening air to catch my tube home and I'm sick of it. Glancing across at the clock on my office wall, I see that it's almost 5.30pm and on the spur of the moment, I decide to leave work early. I haven't actually done anything constructive for at least an hour and if I sit...