When I tell people that I have started running quit often the hilarious reply is "What are you running from?" Reading various online forums it seems that people will even shout this from cars at runners.
I'm not going to address the issue of abuse from drivers here but I am going to try to answer the question:
I'm running from myself.
I'm running from the me that tells myself I'm crazy to get up at 6am and go running in the rain.
I'm running from the me that spends far too much time in the work canteen eating more than my share of the latest round of birthday buns.
I'm running from the me that loves eating far too much unhealthy food in restaurants.
I'm running from the me that washes that food down with a pint or two.
I'm running from the me that tells myself I'm never going to finish that run and may as well stop now.
I'm running from the worst version of me towards the better version.