Why are bus drivers late?

You know, I'm sickly with the flu right now, so I generally wait until the last minute to get Sam off the bus-  It's freezing, especially to a feverish, achy person.  So I get outside at 1:08, and his bus comes at 1:10 on Mondays because it's a half day.  It didn't come until 1:25!  I asked Sam why his bus was so late and his reply was "I think the bus driver was in Florida!"