Johnny Robbins

[Vimto]

When I was a small boy and speculating on outlandish speculations or generally being fanciful my Mother used to say, "Don't fill your head full of Johnny Robbins" or something similar which I understood to mean "stop talking nonsense". I have never been able to find any reference to this saying. I grew up in Clitheroe in Lancashire adjacent to the Yorkshire border. Can anyone please suggest or indeed, pinpoint the origin of this expression?