After the first 8000 miles my confidence had reach the level of feeling pretty indestructible, then I binned it at a decent speed on the way to work Then over the next 1000 miles it came back again, but with a healthy respect for the road surface and the harm it can cause. Then I skidded out on a patch of diesel, and it went again, but not quite as much. Back again after a couple of hundred miles, and to be honest probably better than ever because I now had a little bit of first hand experience of worst case scenarios. Helps me stay calm, in a weird sort of way. By the time I'd done a total of 13,000 miles I felt pretty damn confident and utterly aced my Mod1 and Mod2. Clean sheet, which made me feel my confidence was justified. Then I got my BMW, which constantly fails me in new and creative ways, and on many occasions has been ridden home from work in less-than-roadworthy condition. Now I'm not sure if my confidence in my riding has dwindled, or just in riding that particular bike, but I know my riding has suffered and I don't chuck it around like I used to. What I'm trying to say is, I think it's more about the experiences you accumulate, rather than how long you ride for or how many miles.