I was stationary on my motorbike and got shunted by a young lad in a car. I was giving way, indicating, weather was clear and it was broad daylight. How was I > 0% to blame?

You have a share of blame.
I didn't say too blame(as in 100%) or the cause.

Well....here is the thing that makes you have some small blame....
Had you have not gone out on your motorcycle that day....you wouldn't have been rear shunted. That is your blame...that small piece of blame is enough if a passenger was on your bike and possibly a passenger in the offenders car, to make a claim against you, should the driver be uninsured!

You don't need "blame" to start a civil action. Anyone can attempt a civil action over anything. Whether it succeeds or not is another matter.

I'm going to stay in today, in case I get a % of blame for anything else.

Dunno what planet you lads live on, but my situation seems to be unique: anything goes wrong in our household and I automatically get 100% of the blame. Even if I was down the pub at the time.

Please tell me I'm not alone.