Obviously smarter than your average burros!

Then there was the time (at age 16) I parked my parents' pickup in a campground at the Grand Canyon, and left it in neutral with the parking brake on, forgetting that my mother had driven the truck with the parking brake on so many times that it didn't work. The pickup headed straight for the canyon rim, with (as far as we could tell) only some scrub trees in the way. Fortunately, my mother was able to get inside and stop it before it got going too fast.

While my husband was studying for his master's degree, one of the employees on the university's horticulture farm, whom husband was supposed to be supervising, managed to do something similar with a tractor, which promptly headed for the farm pond. It was pulled out and dried out, but the process was somewhat expensive.