Bicycling 30:00 
The 1st & 2nd graders, then the last group of 7th graders, for my lecture.
Decided to start my lectures this year with a joke. This woman starts getting really bad headaches, so she goes to the doctor. Doctor says, bad news, you've got brain cancer & 6 months to live. Unless you want to try this new experimental treatment: brain transplant. Woman says, yeah, OK, I'll do that. Doc says, you have two brains to choose from, one from an orienteer and the other from a track star. Woman says, OK, what's the difference? Doc says, well, the orienteer's brain costs $85,000 and the track star's brain costs $400,000. Whoa, says the woman, why so much less for the orienteer's brain? Doc says, well, it's used.
Not the greatest joke, especially given that there are kids who run track.