Yeah...."How do you do it ( anyone on the board? ) - how do you get through your day everyday? Knowing that tomorrow will invariably be the same, that nothing changes and the only things that do change"

Good question.....there are a lot of things that keep me from going insane.
Youth is the main one, due to the stunning history of "mental illness" in my family.
Aside from that:

In my day-to-day life, I am surrounded by people that are interesting. My group of coworkers is makes life easier. It is a rare occurrence to have a day where we don't spend a great deal of our time working making jokes and quoting various pop-culture sources (mainly "The Simpsons").

Hobbies....or whatever you call them. Dreams, I suppose. Doing what I want on the weekend: cars, fishing, hunting and enjoying the outdoors. The idea that if I (we) work hard enough, then maybe (just maybe) it will be possible to make a career out of doing what we like to do. Talking to guys who do race for a living, it's mainly luck, getting noticed by the right people at the right time is what it takes...So you cling to the idea that if you branch out and do a lot of things, someone might take notice. Even if not, it's still a kick in the ass to do.

The last major factor that helps contribute to my making it through the day...Alcohol.
As Homer Simpson put it: "Ah, beer. The cause of, and solution to, many of life's little problems."
Many experts say that drinking doesn't make problems go away....it sure as hell makes them less troublesome, though.

That's how I get through my day....it seems to work, and I'm sure there are things I overlooked in this.