This is when you really test your freeze, flight or fight skills. Every molecule in your body is saying "RUN! There's something coming at you really fast. Move! Now!". There's a reason for it. It makes sense to get out of harms way.
The rational side of your brain is saying "Stand still. If you stand still they won't hit you." It is really hard not to bitch slap the rational part of your brain and take off at a full sprint. But if you do, you will end up being plowed down by 65 pounds of muscle going 30 MPH. And when that happens it's gonna' hurt.