80 mpw on singles only is going to leave you tired most of the day. Start doubling and potentially adding more mileage, and you'll be even worse off, meaning you won't do as well of a job (in your day job) as you could.
There are a few problems with your idiotic statement about being fired tomorrow. One, many of us aren't making minimum wage and just because we're not self employed doesn't mean we aren't very important to the companies we work for. And two, many of us would like to continue to be important and continue to move up the ranks, being tired and doing a poor job does not allow for that. Sure, we could be fired tomorrow, but thinking like that will leave you exactly where it sounds like you currently are, in a crappy job where no one cares about you making no money. If you ever want to be promoted into senior positions and make more money, then you put time into your job, not so you can make your boss more money as you seem to think, but so you can advance your own career.