I started working exactly 17 years ago. The next time I call in sick to work will be the first time. (Its not going to happen, so don't hold your breath.) I'm pretty sure there is nothing in this world that I fell more strongly about.
For the first several years, I didn't even think about it. I showed up to work, because that was what I was supposed to do. For the last 4 or 5 years, it has become an obsession.
I am no where near perfect, but my attendance is.