Riding on a bike path is really no different than riding on the road in the sense that you still have to be aware of your surroundings. Just like in the road, you can't assume that anyone is watching out for you, you have to watch for yourself. People's unwillingness/ignorance to "share the path" is no different than people's unwillingness/ignorance to sharing the road. The difference now is that you are the fast traffic, not the cars. That said, the bike path is no place for a cyclist to "train". Consider it a recreational ride and enjoy the scenery.