DS1 nearly 4 just ran off as I picked him up from nursery and ran across a (quiet -thank god) road to a sweet shop. He normally stops at the edge of the pavement but today he was with a friend as he left nursery and they both bolted. I am trying to make him see how dangerous it was, have got back home and drawn pictures etc but I feel we need to hammer home the message before he forgets what happened. When I ask him why he wasn't allowed to buy any sweets (as punishment) he doesn't know - help!