My housemate Paul has been riding dirt bikes every week or two for the past few years, and every now and then he asks if I want to go with him. I finally went, to Hollister Hills, and it was lots of fun.
I'd never riden a motorcycle before. I was using a 4-stroke 125cc bike that weighed just a bit more than me (which means it was pretty light). Paul taught me the controls, and I drove up and down the parking lot once. Then I went on the beginner track for 15 minutes or so.
I picked it all up pretty quickly, so after a break, I went on the grown-up track for a while, which was more challenging. I imagine my presence as a slow moving obstacle made it more challenging for everyone else too, but no one seemed to mind. At one point I even passed someone else who was clearly just starting out.
Then we went on some trails. We were joined by Carlos, who we'd just met at the camp site (parking lot). We went around the entire park, on both beginner and intermediate trails, and got some great views. I think we went about 20 miles.
Carlos, me, and Paul, after our ride. If you look closely, you can see lots of dirt on my face!