If we were left in the car for a few minutes in the High Street while our mother went shopping, and we saw a policeman coming, we would dive between the front and back seats. No idea why - even then I was asking myself this at the back of my mind. Perhaps we didn't want our Mum to get into trouble for leaving her children unattended while she popped in to pick up a newspaper.
Otherwise I am pretty sure I didn't have such a wondrous childhood - none of the above ring a bell, not even the rose petal thing. I just took everything as it was. I'd probably walked under several ladders before anyone told me it was unlucky to do so.
In another thread, I have said that my eldest son, even when quite small, was quite clear about what was real and what wasn't and would wonder how they did some of the special effects and "magic" on television. That was me when I was little. Doctor Who never scared me. Firstly, it was in black and white, and secondly, the scenery always looked so home made. I did wonder how they found people small enough to get inside the daleks to operate them.