All things equal, it's better to have learned in the dirt
Most of these posts are right on the money. I'm a semi-geezer at 45, and learned to ride in the woods back when the XR 600 was king. I later moved on to a host of 2-stroke machines that taught me about big power coming in very small packages. No one can argue against the skill set developed through riding off road, where the terrain changes by the foot, and the bike is always floating under you in a state of constant over / understeer. Here in VT, the roads are a constant mess, with most of the asphalt connecting to gravel. There are often huge sections that come out of nowhere that contain marble sized gravel and sand to catch you out. The "old and bold" comment is accurate as hell.