There are several reasons.

Our front yard as photographed from inside, through one of the front windows, a few weeks ago.

There are several reasons that my kids are playing the Wii Sports today for exercise.  The first is that it's raining and although they have been out in the yard several times today, they don't want to have to be outside for exercise.  It's different, you know?  Exercise is on their list every day and they have to do an hour, and they usually do this outside but it's deer season and we live in the woods and over the weekend, we heard a lot of gunshots.  People aren't supposed to hunt on our land, but they might wound a deer on another person's land and follow it onto ours to finish it off.  If we do go outside of the front yard for our later "15 minutes outside with mom", I'm going to wear something more bright than my basic normal black.  :-)