Weekends make me tired

Holy cow. I worked harder this weekend than I did all week. We're having a gorgeous spate of indian summer, and I didn't want to spend it all in the basement, so we got out in the yard, brought in the lawn furniture, cleaned up and raked a little, and had a lovely fire going. Now I smell like smoke and I'm ready for bed. But it's a good tired. What the heck does that mean, anyway?