it is very beneficial to ride a street bike on smoother grass or 1 inch deep or less gravel. You feel the bike moving under you, learn to relax and let it. Yet it is not challenging enough to make a crash likely. Then on the street when you encounter road construction, or gravel or sand in the corners, you do not freak, grab tight and crash. You relax, let the bike have its way a bit and steer out of it. Now 2 track or single track is not a good idea when you are older. I have been lost bad, rode hard arkansas 2 track on my RS, I did not fall, and like all adventures, it was more fun after it was over than during it. It can be done, and it should be avoided. I do not want to try that again.